To change the administrative password for your current Drupal installation you should:
1. Go to your cPanel -> Databases box -> phpMyAdmin;
2. Select the database which Drupal use from the drop-down menu on the left.
4. Click on the SQL tab.
5. In the text field on the page type the following text:
update users set pass=md5(‘NEWPASS’) where uid = 1;
Change “NEWPASS” with the desired new administrative password. Then click on the GO button and if no errors present, the Drupal password should have been changed.