How do I change Apple ID?

Did you forget your ID or are you trying to do an email address name change in the ID?

See if you can recover the ID/password.

Apple ID - How to find your Apple    An iCloud e-mail address is an Apple ID.

Apple ID - Find              

Enter the Apple (iCloud) ID and click Forgot Password.

Apple ID - Manage            

Apple ID – Forgot Password            

To change the email address, see below. Note the restrictions in the article.

Apple ID Name Change.        

 What to do after you change your Apple ID or password - Apple Support    I suggest doing this before you change your Apple ID or password.