ID

Change the email address? Note the restrictions in the article.

Apple ID Name Change.        

 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.

If you create/use a new Apple ID, you will lose access to some of your data and the purchases made with your existing Apple ID. You might want to explain what problems you are having with your current ID to see if someone can make suggestions that will fix your current ID problems.

Apple ID - create a new.      

Apple ID – Create        

Apple ID - Could Not Create or Could Not Set Up iCloud message.