Change email in Apple ID

iPhone, iPad, or Mac: 

1. Go to Settings or System Settings, then choose [your name].
2. Tap or click Sign-In & Security.
3. Tap or click your primary email address to make changes.
4. To remove this email address from your account, select Remove from Account. If you want to keep the current email address associated with your Apple Account but change to a different primary email address, turn off Primary Email.

Change your Apple Account primary email address on the web

1. Go to account.apple.com, then Sign in
2. Go to Sign-in and Security
3. Click Email & Phone Numbers
4. Click on the minus to remove an email.
5. Enter another email as the new primary.