Currently Being ModeratedAug 28, 2013 8:43 AM (in response to jak949806)
Any purchases on the device which are no longer available in the iTunes Store will be lost during the process unless transferred to the computer first. If you want, you can launch iTunes with the Option key held down and create a new iTunes library to store them, which can be on an external drive.
Currently Being ModeratedAug 28, 2013 8:50 AM (in response to jak949806)
You will need a computer running iTunes to update the iPad 2 from iOS 4 to anything above that (iOS 5 or 6). If I was in your shoes, I would create a new user account on your computer. Log on to your computer as the new user. Then authorize iTunes in that user account using the teacher's Apple ID. Run a backup of the iPad 2. Then update the iPad 2 to the latest OS.
If you have problems running a backup, you could try backing up some of the app data to a cloud service like Dropbox for apps that offer Dropbox integration.
Hope this helps!