<!-- from fixya rte -->How do I CHANGE MY iTunes Email address - Apple iPod touch

1. Open iTunes. Make sure that you have the latest version.

2. From the menu bar at the top of your computer screen or at the top of the iTunes window, choose Account > Sign In. Then click Create New Apple ID

3.Read and agree to the Terms and Conditions and Apple Privacy Policy.

4.Complete the form to create your new Apple ID. The email address you provide will be your new Apple ID. The form also includes security questions for your protection, and asks for an optional rescue email address. We recommend providing a rescue email address.

5.After you've filled out the form, click Continue.
If you see a message that says that the email address you entered is already associated with an Apple ID, follow these instructions to use an existing Apple ID instead.

6.Enter your credit card and billing information, then click Continue. We'll charge you only when you make a purchase. You can change or remove your payment details later.

7.Check your email for a verification email from Apple and follow the steps to verify your email address.
After you verify your email address, you can sign in to the iTunes Store and other Apple services such as iCloud with your new Apple ID.

Logon to your ITunes account online and change the account details.

For doing things like downloading and updating apps, making purchases from iTunes, and making FaceTime calls, you'll need an Apple ID. If you don't already have an Apple ID, this article will show you how to create one.
Steps

1. 
   1
   Turn on and unlock your iPhone. Enter your passcode if your device requires one.
   
   Ad
   
2. 
   2
   Tap the Settings app from the Home Screen.
3. 3
   Scroll down until you see the "iTunes and App Stores" entry.
4. 4
   Tap "iTunes & App Stores". If an existing Apple ID is already signed in, sign out of it before proceeding.
5. 5
   Tap "Create New Apple ID".
6. 6
   Find and select the country you're located in. Tap Done to confirm your selection and then Next to proceed.
7. 7
   Read over the iTunes Store Terms and Conditions and agree to it. Scroll to the bottom of the page and tap "Agree"; tap it again at the alert that shows. If you have trouble reading the document, you can choose to have it emailed to you by tapping "Send by Email" and entering a valid email address.
8. 8
   Fill in your email address, a password, three security questions with their appropriate answers, and your birth date. Your password must have at least 8 characters (including a number and an uppercase and lowercase letter) with no spaces. It also shouldn't have three consecutive characters (ggg), be your Apple ID, or a previous password you've used in the last year. After registration, your email address will become your Apple ID.
9. 9
   Enter your billing information. To make an Apple ID, a payment method needs to be provided in the form of a debit card (Visa, MasterCard, or American Express), iTunes gift card, or iTunes gift certificate.
   
   
   • Understand that your card will not be charged until you make a purchase of apaid app. For free apps, you will never be charged.
   • Your billing address will also need to be provided, which consists of your full name, street address, city name, state/province name, postal code, and phone number. This is just for confirmation of your payment information, and receipts of any purchase you make will be emailed to you, rather than through a postal service.
10. 10
    Verify your account. An email will be sent to the email address you've provided.
11. 11
    Log into your email account and look for an email from Apple. The subject line will be "Please verify the contact email address for your Apple ID." Open it and click the link to verify your account.
12. 12
    Sign in with your Apple ID credentials on the Apple website, and click "Verify Address". If it works, you are now the newest owner of an Apple ID!

I want to tell you that if you change your Apple ID with same primary email address then all purchases will now be linked to the new Id and primary email. for changing your Apple ID follow this tutorial http://support.apple.com/kb/HT5621 and if need some guidance during this process follow Mac Support .

1. Sign out of iCloud, the iTunes Store, App Store, FaceTime, Find My Friends, Find My iPhone, and iMessage on each device that uses your current Apple ID for these services.

1. Go to My Apple ID (appleid.apple.com).

1. Select "Manage your Apple ID" and sign in. Forgot your password?

1. Select Edit next to "Apple ID and Primary Email Address."

1. Enter the email address to use as your Apple ID, then select Save Changes. Apple will send a verification email to that address.

1. Open the email from Apple, then click Verify Now in the email. Didn't receive the email?

1. When the My Apple ID page opens, sign in with your renamed Apple ID.

1. When you see a message that verification is complete, you can begin using your renamed Apple ID. You should also update the features and services that you use with Apple ID.

source: http://support.apple.com/kb/ht5621

You need to go to iTunes online, sign in with your old email address then go to settings and update your contact information.

Try connecting it to iTunes and check in devices option. Should help

Change the Default Email on an iTunes Account
If you want to purchase and download items from the iTunes Store, iTunes requires that you create an account.
It uses the email given during registration as your default Apple ID for logging into iTunes services and for sending receipts for purchases.
If your primary email address changes, you can edit your account information to use a new default email address.

Launch iTunes, and then select "Sign In" from the "Store" toolbar menu.
Type your current account credentials and click "Sign In."
Select "View My Account" from the "Store" menu, type your account credentials again and then click "View Account."
Click the "Edit" button beside your Apple ID on the "Account Information" page.

Type the new email you want to use beside "Email," and then click "Done" to change the default email address associated with your iTunes account.

Changing account information
http://support.apple.com/kb/HT1918



Access an iTunes Account From Another Computer
Your iTunes account allows you to purchase music, videos, and other types of media directly from the iTunes Store, and can be accessed from a number of devices, including your iPhone.
In order to access your iTunes account from another computer, you must enter your account information into the Sign In page of the iTunes program.
Once signed in, you can authorize the computer to play media purchased from the iTunes Store and set up other iTunes-exclusive features, including Home Sharing.

Click "Start" on your Windows PC's taskbar, then click "Programs," "Apple," and "iTunes" to run the program.
For Macintosh computers, open the Applications folder in "Finder" and double-click the "iTunes" icon.
Click the "iTunes Store" tab, then click the "Sign In" button on the right side of the program window.

Type in your registered Apple I.D. email address and password, and click the "Sign In" button.
Click the tab in the upper-right corner of the iTunes Store window with your email address on it, and type in your account password.
Click the "View Account" button to access your iTunes account.
Click the tabs on the right side of the window to access different areas of the account.
Click the "Done" tab to save and exit out of your account settings.

http://support.apple.com/kb/ht2731


Change My iTunes Account Settings
Apple iTunes is a digital media player that you can use to download and play audio, video, podcast and television shows.
It's compatible with both the Windows and Mac operating systems and it can sync its files with the iPod, iPhone and iPad.
Your account settings are used to manage your iTunes account and store your email address, payment information and password.
If you wish to change your settings, you can do so in a few clicks.
Launch the iTunes application on the desktop.
Sign in with your iTunes user name and password.
Click the "Store" link at the top of the screen.
Click "View My Account" type in your password, then click "View My Account" once more.
Click "Edit."
Select the settings you wish to change such as email address, password or payment options by highlighting them and changing the information in the boxes.
Click "Done" when you have made your changes.
Changing account information
http://support.apple.com/kb/HT1918

To create your iTunes Store account:

1. From inside the App Store or iTunes Store tap Sign In at the bottom of the page.
2. When the prompt appears, tap Create New Account.
3. Choose the appropriate store by tapping on Store, and select the country in which you reside. Tap Done to confirm your selection, then tap Next to proceed to the next screen.
4. The next screen will display the iTunes Store Terms and Conditions. You can opt to have the Terms and Conditions emailed to you for easier reading by tapping Send by Email. Enter your valid email address then tap Send.
5. After you've read through the Terms and Conditions tap Agree, located in the bottom right of the page. Then again when the confirmation appears.
   
6. Once you've agreed to the terms and conditions, you'll need to input your preferred email address and password along with answers to some security questions. The email address you provide will be your new Apple ID as well as your iTunes Store account username. Tap Next.
7. 
   Tip: If you are trying to create an account using your MobileMe email address, you will receive a prompt telling you that your email address is already an Apple ID. Simply tap Continue, then tap Use Existing Account on the following screen.
   
8. Next, you'll be required to enter your billing information. To change the default card type, tap the Credit Card field. Select your card type and tap Done. You will not be charged until you make a purchase.
   
9. Once you've filled out all the fields for your billing information, tap Next to complete your account creation. You'll receive a notification that your account has been successfully created.
10. Tap Done to go to the App Store or iTunes Store to begin browsing the store.

And there you Go.....