Your Magic profile
The profile component allows you to edit your profile, such as changing your user’s password for instance, in addition to changing what theme you want to use, etc.
Notice, Magic does not allow you to change your email address, and your username, once a user has been created. This would require double optin verification of the email address, and also possibly referential integrity issues for changing usernames. You can change your name, and/or your password though.