Actually you can.
1. Create a new Administrator user with a different email you have access to, but NOT the email you want to permanently use. (This user will be deleted, so info does not really matter, but make sure you use a good email just in case you get locked out!)
2. Log out of current admin user that you want to change the username/email.
3. Log into the new Administrator user you just created in step 1.
4. Delete the Administrator user account that you want to change the username/email.
5. Attribute all the current articles/posts to the new user you just made. (This is asked when you delete the user.)
6. Create a new Administrator user, with the new username/email you were trying to use.
7. Log out.
8. Log in using credentials made in step 6.
9. Delete the user you created in step 1, and attribute the current articles/posts back to you (current user).
That’s it! Hope this helps.
