To terminate an account in WHM :

1. Login to your WHM Control Panel
2. Click 'Terminate Account' on the left-hand side of the screen in the Account Functions section
   
   The following page will show you two boxes: onet hat lists all the current domains and one that lists all the current users.
   
   
3. If you want to remove a domain entirely select it from the box on the left and click the Terminate button
4. If you only want to remove a user account select an account from the box on the right and click the Terminate button 

Once you have performed either one of these you will be taken to a page telling you the account has been terminated.