Extending @grgarside's answer:
- Acquire iTools, iFunbox, and a Windows or Mac desktop computer
- Use iTools to backup the apps to desktop
- Uninstall all apps
- change AppleID for App store, iCloud, etc. everywhere on device
- Power off/on cycle
- Reinstall the apps from App store (not from backup!)
- On desktop computer, unzip the
.ipa
files to a staging area
- With iFunbox, for each application:
- Manage Files and
- copy
Documents
and Library
from {desktop}\staging_area\{app name}\Container\
to {i-thing]\User Applications\{app name}\
...and you should be good to go.
Notes:
Strictly speaking, you should be able to use iFunbox for everything. However it crashed frequently on my Win7 system so I'm not inclined to use it more than necessary.
.ipa
files are just zip archives with a different extension. You may need to rename .zip
in order to extract the contents.
The reason for #3 and #6 is that the appleid is welded into the app before it is downloaded and installed. For the same reason we don't use either management app's native restore mechanism.
If the device is jailbroken you might be able to use iTools for the whole process. (On the unbroken ipad I was using the iTools file system view did not show the User Application data.)
This recipe worked for the half dozen apps I needed to move, but I expect some apps have a more complicated process, e.g. copy X,Y,Z from Documents, but leave behind T,U,V and edit the headers in W,X to the new account into.