From the additional services form on the support page:
"Domain Change Request
For customers which have placed an order for a hosting account within the last 30 days, Surpass Hosting will change the domain name used on the account at no additional charge. Simply visit
http://desk.surpasshosting.com/ and submit a request to the Sales Division for this change.
To change the domain name on a hosting account 30 days after the initial setup, a $10 fee is required for the reconfiguration of the hosting account to use the new domain name."