I have a new mini iPad 4 to replace my slow iPad. I set it up as a new device and am unsure how to go back change that so I can get all I have on my slow iPad onto my new mini!

It's easy. There takes transferring music as an instance. Just follow the below steps.

Step 1 Start Leawo iTransfer

Connect old iPad to computer via USB cable. Start Leawo iTransfer on your computer. The software will automatically recognize your device and shows iPad library in the left sidebar.
Step 2 Select music to transfer

Click the name of iPhone and go to "LIBRARY > Music" in the left sidebar and select multiple songs in the right interface by holding "Ctrl". Right click them to choose "Transfer to > My Computer".
Step 3 Transfer music from iPad to computer

In the pop-up window, chose "Save to folder" and click on "Change" to select an output directory on your computer. After that, choose "Transfer Now" to transfer music from iPad to your computer.
Step 4 Transfer music from old iPad to new iPad

Disconnect iPad but connect new iPad to your computer. Go to "iPad > LIBRARY > Music" in the left sidebar. Choose "File > Add > Add File or Add Folder" in the top middle to upload music you just transferred from old iPad to your new iPad.

For more details, check: How to Transfer Music from iPad to iPad

iTunes enables you to restore iPad mini to factory settings. Before you start restoring iPad to factory settings, please note that you need to install the latest version of iTunes on your Windows computer or MAC. Then go to Settings > iCloud to turn off Find My iPhone. Now, you can factory reset your iPad with iTunes as follows.

1. Plug iPad into the computer with the USB cable. The iTunes on your computer will automatically launch. If not, double-click the icon to start it.
2. Click the name of your iPad at the upper right corner of iTunes, and then the information of your iPad will be shown. Click the "Restore iPhone" button in the window to start.
3. iTunes will ask whether you want to back up iPad before restoring. You'd better choose "Yes" for the reset will erase the contents in your iPad. Then iTunes will start restoring your tablet to factory settings.
4. Click Restore again to confirm. Then iTunes erases your iPad and installs the latest iOS software. After you restore your device to factory settings, it will restart. Now you can set it up as new.

http://www.leawo.org/tutorial/how-to-restore-iphone-6-plus-to-factory-settings.html

In your settimgs go to back up/restore. There should be the option to factory reset your device. Click it, after confirming you want to reset, your device will reset back to its original settings.

The following can be done on ipad with iOS 8:
1. Press the home button( the round button on the front side of your ipad), to go to the home screen.
2. Find the Settings icon ( looks like gray clockwork gears) and tap on it to launch the Settings app.
3. After settings app is started try to find on the left side of the screen Passcode ( has a red lock icon near the text) and tap on it
4. In the passcode setting screen you can choose the type of passcode with the Simple passcode setting switched on or off ( simple means a 4 digit number, not simple means any character combination
5. By taping on Turn passcode on you can enter your passcode. Be carefull not to forget your passcode, otherwise you will not be able to use your ipad later.

You will have to restore it by connecting to iTunes on your computer. That will erase all settings including the password. If you have a backup you can get it then set up as a new device with a new password.

It is called ghosting and has been a major issue for the Mini thus far (even though it hasn't been reported in the MSM).

Play with your settings to find a way where it effects you less-- screen brightness, motion detection, reset the device and restore to original settings (but back your Mini up first!).

What wrong with your iPad 3? Maybe you can reply on the tablet replacement repair parts for iPad 3 to make your iPad return back new and health. Nowdays, there are more repair parts for fixing the unflexible and scracked.

If you want to sync new apps to iPhone and iPad, you can take advantage of the "Automatic Downloads" function of iTunes. You only need to tap Settings > iTunes & App Store, and locate AUTOMATIC DOWNLOADS, then turn on Apps and Updates. Finish the steps on your iPhone and iPad so that you can get apps on the other devices when you finish a download on one device. You can also take advantage of the third-party iPhone transfer software, Leawo iTransfer, to sync iPhone apps to iPad. The software can transfer files among iOS devices, iTunes and PCs, and it transfers app data when users want to transfer apps. The following guidance will show you how to sync iPhone apps to iPad, and you can download this software and have a try. Download Leawo iTransfer ' Leawo iTransfer for Mac and install it.
Step 1. Run Leawo iTransfer and connect both device to computer with USB cable. Then your devices will be shown on the main interface of the software.

Step 2. Click your iPhone and choose Apps in the left sidebar. The contents will show up in the right part.

Step 3. Select the apps you want to transfer, and click the transfer button at the right bottom.

Step 4. Check Transfer to List and choose iPad as the target. Then click Transfer Now. Then the iPhone apps you selected will be transferred to iPad in several minutes.



For more detail, check: How to Sync iPhone Apps to iPad