Q: I was reading your article on Moving from a shared iCloud to individual accounts, which looks like what I want to do. However, will this transfer all of my apps, pictures and calendars to my new iCloud account?
A: Unfortunately there is no way to automatically transfer information between two iCloud accounts on the back end, so when you create a new iCloud account, it essentially begins as an empty shell. Transferring your information into it must be done from a computer or iOS device.
Personal information such as contacts, calendars, bookmarks, and reminders would need to be re-uploaded to the new iCloud account from your iOS device or your Mac or PC. If you’re a Mac user, the Calendar and Contacts apps in OS X Mountain Lion are the easiest way to do this, but it can be done from an iOS device as well. When disabling or deleting your current iCloud account, simply be sure to choose the option to keep these items on your device; any information in these categories found on your device will automatically be synced up to your new iCloud account once you’ve created it and signed in on your device.
Your Photo Streams, including Shared Photo Streams, will simply be removed from your device once you’ve signed out of your old iCloud account. If you’re using iPhoto or Aperture on a Mac or the iCloud Control Panel for Windows on a PC these photos should have already been downloaded to your computer. You can later manually push these back into your Photo Stream and re-create any Shared Photo Streams using these apps, or simply start over. Since the Photo Stream isn’t designed to be a permanent repository of your photos—only a maximum of 1,000 photos or 30 days of photos are retained—you should be saving them on your Mac or PC anyway. Note that local photos stored in your Camera Roll on your iOS devices or synced from iTunes are unrelated to iCloud and will be untouched.
iCloud Documents & Data is a special case.
This data will be removed when you delete your iCloud account from your iOS device, however the impact of this will depend on the specific applications that you’re using on your iPhone, iPad, or iPod touch. Applications that provide local storage and simply sync their data with iCloud should be able to push that data back up again, while other appellations may rely on iCloud completely. In the latter case, if at all possible you should export your data from these apps and save it elsewhere until you have setup the new iCloud account. This is unfortunately an app-by-app situation so there’s no standard answer as to how this will be handled, although many apps do provide the option for both iCloud-based and local storage, so simply ensure that any important data such as saved games or documents are in a non-iCloud storage area.
If you’re using iCloud for e-mail, this is a particularly special case. Your e-mail is not stored locally on your iOS device, and deleting or disabling your iCloud account will simply delete the mail from your device, although it will still remain on the iCloud servers.