Change Apple ID

You can change your existing ID to a new email address. That allows you to continue to access your data and previous purchases.

Note the restrictions in the article.

Apple ID Name Change. https://support.apple.com/en-us/HT202667

 What to do after you change your Apple ID or password - Apple Support     https://support.apple.com/en-us/HT204071 I suggest doing this before you change your Apple ID or password.