Changing your GitHub username
You can change your GitHub username at any time.After you’ve renamed your user account, update the remote repository URL in any local clones of your repositories. For more information, see What happens when I change my user name?
1-In the top right corner of any page, click your profile photo, then click Settings.
2-In the left sidebar, click Account settings.
3-In the “Change username” section, click Change username.