How to reset WHMCS admin password
Password for WHMCS installation can be changed in two different ways:
Reset via the website
To request WHMCS admin password reset at the login window:
Only type in your email address for the installation
If the email address is correct, the form should automatically send the password reminder email so that you can recover access to your WHMCS website profile.
To reset through the database
In case the password reset email does not get to your email box You can follow these steps to reset the password through database:
a. Log into your cPanel.
b. Go to Databases section > phpMyAdmin menu:
c. Once inside, find the database in question and look for the tbladmins table. Click on Edit next to the admin user in question:
If you do not recall the database name of your WHMCS installation, check the configuration.php file located in the root folder:
d. On the next page look for the password column. In the last field enter the new password and select the MD5 hash option.
In the passwordhash column, remove the value from the last field:
e. Once done, scroll down to the bottom of the page and click on Go.
Hope this helps...