If by some reason you need to change the login for your Git repository you'll find out that there is no way to do this from SourceTree. To do that you need to use terminal:
- Open SourceTree and navigate to the repository you want to update the password of
- Click the ‘Terminal’ button on a toolbar to jump to the location of the repo on the command line
- Enter ‘git pull’ command to update the repository
- Then you are requested enter your login & password
- Done
UPDATE: Tools->Options->Authentication. SourceTree seems to use this and not the username specified on the actual remote anymore.
