Q: I have changed my apple id email, but how to change the icloud apple id on my ipad

Hello Li Minghan,

You may need to temporarily revert the changes made to your Apple ID in order to sign out of iCloud on your device.

1. Change your Apple ID to the Apple ID you used previously. You shouldn't need to verify the email address.
2. Go to Settings > iCloud. Complete these steps only if the Find My [Device] setting is turned on:
   • Scroll down and tap Delete Account, then tap Delete to confirm.
   • Tap “Keep on My [Device]” or “Delete from My [Device].” In either case, your data remains in iCloud and will be updated on your device when you sign in to iCloud again.
   • Enter the password for your previous Apple ID.
3. Change your Apple ID to the new email address that you want to use. You'll need to verify the email address.
4. Return to Settings > iCloud and sign in with your new Apple ID.

iOS 7: If you're asked for the password to your previous Apple ID when signing out of iCloud

http://support.apple.com/kb/TS5223

Cheers,

Allen

Li Minghan,

Thank you for using the Apple Support Community. Due to the nature of your issue or question you may find more information by using another one of Apple's support resources - https://getsupport.apple.com/GetproductgroupList.action.

All my best,

Allen