You can easily modify aspects of a cPanel account in WHM such as the domain name or username of an account. In this video we cover the two ways in which you can modify one of your accounts.
http://www.inmotionhosting.com/support/edu/whm/creating-and-managing-accounts/modify-an-account
Duration: 3:12
Publisher: InMotion Hosting
You can watch this video also at the source.