How do I change the email from my Apple ID?

From:

Change your Apple ID - Apple Support

- There's special instructions if you want to change your Apple ID to an @icloud.com address.

"If you try to change your Apple ID to an @icloud.com email address that was created within the last 30 days, you will be asked to try again later."

Personally I would not use the same iCloud mail address for your Apple ID. If you have problems with your account you also could not get access to the emails Apple sends you helping you with recovering your account.

You'll have to come up with another email address that Apple hasn't seen before. Apple doesn't have any document about reusing email addresses but generally they won't let you use one that has been seen with its system before.