How do I change my Apple ID

Please click on the links and read the documents -->

Change your Apple ID - https://support.apple.com/HT202667 - "Follow these steps to change the email address that you use as your Apple ID."

"After you change your Apple ID email address or password, you might need to update your sign-in information with any Apple services you're using" Click on this link to read "What to do after [or before] you change your Apple ID email address or password" --> https://support.apple.com/HT204071

- You may wish to disable Settings > Find My before changing your information, change the information, then reactivate it with the new information.

If you instead mean change the one that is on the iPhone to a different Apple ID, sign out of the old one if necessary; sign in with the new one.

Sign out of iCloud on your iPhone, iPad, iPod touch, Apple TV, or Mac --> https://support.apple.com/HT208242

If another Apple ID is signed in you may need to enter the password for that ID to sign out of that ID first.

Click on this link to learn how to 'Sign in with your Apple ID' --> https://support.apple.com/HT204053