Whonami-How to change your account’s domain names

In order to change the primary cheap domain names on a hosting account lets you change the domain name associated with account’s Web root directory.

There are something to remember: 

1- If you already added the domain name you want to use as your primary hosted domain name, you need to remove it first. You might also need to remove any subdomains of your primary domain name before you can change it. For more information, see Remove domains.

2- If you have an SSL certificate applied to your hosting account, you cannot change your primary hosted domain name without revoking your SSL. For more information, see Revoking an SSL Certificate.

3- WordPress® installations can break when you change your primary domain. If they do, see the instructions on WordPress’s site.

Log in to your Account Manager.
Click Web Hosting.
Next to the hosting account you want to use, click Manage.
From the More menu, select Hosted Domains.
Select your primary hosted domain, and then click Change Primary.
Enter the new primary domain for your account, and then click OK.