Use this file to reset the admin password when locked out of a concrete5 installation

Copy the concrete5lockpick.php file to the root of your concrete5 installation. The same location as index.php. Browse to http://www.example.com/c5lockpick.php and enter in the username you wish to change and the new password for that user.

Should work from concrete5 version 5.5 up until version 5.7 Version 8 currently does not work. See Concrete5 Super User Recovery

Delete this file immediately after you have reset your password. This file will allow anyone who visits it to change the password for any username on the site. It is very important that you delete this file immediately after use. You have been warned.

See issue tracker