how do I edit an account

Log into the account at the Adobe web site (using old email/password, of course)

Goto My Adobe, then My Adobe ID.

or direct to https://www.adobe.com/uk/account/account-information.html#myadobeid

Put in the new information, and a Save my Changes button will appear.

Press that when ready.

ADE may still show your old email address for a time if you ask about authorization information.

It seems to update itself after a bit.