If you happen to lock yourself out of firstname.lastname@example.org account accidentally, or you forgot the password for it, you can reset the password from Command line.
You can change the password by running the following command:
/docs/sde/live/env/bin/python /docs/sde/live/code/sigma/manage.py changepassword email@example.com
NOTE: In new deployments, you need to run that with sde_admin user, e.g. by adding sudo -u sde_admin before the command.
The newly reset password can be used to login to the web interface.
You can alternatively do it using : Reset Web password SD Elements