Login my gmail account

if your trying to use someone elses computer and it wont let you change the user name go into browser options and use (incognito window) this will let you login.

vincent. Go to browser .
www.gmail.com
notice at bottom of login
sign in
option add account
click on this add account link
then sign in with your account

You should be able to click your icon (of the logged in user) when in Gmail or G+. This should then add a button that says 'Add Account...' , or show alternate accounts previously logged in. Click the other account or the add account button and simply login to switch accounts.
Good luck :)

Hi
If you go here,
Google
then in the middle of the screen is the search box, but at the top right of the window are four to five options, one of which is "Gmail". If you click on this you will load a page where you can input your username and password
Cheers

After it logs in log out and then log back in with her user name and password.

Point your web browser at http://www.gmail.com

If another account comes up, sign out of it by clicking the avatar in the upper-right then clicking "Sign out."

Be sure to sign out of your account when you're done.

Point the web browser at http://www.facebook.com

If another account comes up, log out of it by clicking the down-pointing triangle in the upper-right then clicking "Log Out."

Signing in to your Gmail account gives you access to your email messages.
Gmail Web-based email functions as most email services do, with the option for users to send and receive email messages, store contacts and organize messages.

You can opt to store your Gmail login information when signing in so that you do not need to re-enter it each time you access your email.You can access your Gmail account on a computer or a mobile phone.

Open a Web browser window.
Click the address bar and enter "gmail.com." Press the "Enter" key.

Enter your Gmail username and password in the indicated fields.
Check the "Stay Signed In" box to save your username and password for future logins.

Click "Sign In" and wait for your Gmail account to load.

What do you get when you point your web browser at http://www.gmail.com ? If you're PC is logged in to someone else's account, simply click on the user's avatar in the upper right and select "Sign out."

If it gets straight into his account, then you click on top right hand corner on Sign out and it will take you to the login screen. If you are at the login screen and it's his username and you want to put in your, click on Sign in as a different user and then log in with your credentials.