Apple ID change
how can I change Apple ID back to .me.com
iPad 2
If your e-mail address was associated with the ID in any way, for example as a Reachable at or Rescue e-mail address, then it can't be reused with another Apple ID for approximately one year. You will need to get another e-mail address to use as your Apple ID.
What to do after you change your Apple ID or password - Apple Support I suggest doing this before you change your Apple ID or password.