How do I change the email for my backup

Hello Walkingbuddy,

Welcome to Apple Support Communities. It sounds like you would like to change the Apple ID email that you use for Mac. Right? If so, you can do that by using these steps from Change your Apple ID - Apple Support.

"How to change your Apple ID to a different email address

1. Go to appleid.apple.com and sign in.
2. In the Sign-In and Security section, choose Apple ID.
3. Enter the email address that you want to use as your Apple ID.
4. Choose Change Apple ID.
5. If you changed your Apple ID to a third-party email address, check your email for a verification code, then enter the code. Learn what to do if you didn't get the email.
6. If you use services like iCloud or Messages to share with friends and colleagues, sign in to those services with your updated Apple ID."

The new email address would be the one you'll sign in to on your Mac using this guidance from Sign in to iCloud on all your devices - Apple Support.

"Set up iCloud on your Mac

1. On your Mac, do one of the following:

• macOS Ventura: Choose Apple menu > System Settings, click [your name] at the top of the sidebar, then click iCloud on the right.
  • If you don’t see your name, click Sign in with your Apple ID, enter your Apple ID and password, then click iCloud.
• macOS 12 or earlier: Choose Apple menu > System Preferences, click Apple ID, then click iCloud.
  • If you don’t see Apple ID, click Sign In, enter your Apple ID and password, then click iCloud.

2. Turn on or select each app or feature."

If you need more help, please let us know a bit more about what it is that you'd like to do.

Kind regards.