If you forget the password or need to gain access to the Drupal administrative user account, then you will need to run a SQL command on the Drupal database. Your hosting company can help with giving you access to the right tools to do this. Often PHPMyAdmin is provided which is a web-based tool for SQL commands. Run this command:
UPDATE `users` SET `pass` = MD5('newpassword') WHERE `uid` =1;
newpassword is the new password you’d like to use.