How to delete a MySQL user in WHM.
Sometimes you delete an account and need to recreate the account and the MySQL username is not deleted. And your are unable to remove it. This may require you sign in to WHM and preform this action.
Go to WHM click on phpMyAdmin then click on the database that has the user needed to be deleted. Then enter the following code in the SQL text area.
DROP USER 'username'@'localhost';
Change username to the desired username to delete. I.E. mysite_user.