[joligario]

The username/password are stored in the database under peq_admin. The password for root is just your database root password, not your editor password. If you fill in the username/password in the config, it just auto fills in the username/password you select just so you don't have to type it.

EDIT: Just in case you ask -

UPDATE peq_admin SET login = "new_username", password = MD5("new_password") WHERE id = 1;