You put the appropriate code in the smarty template.
But I don't understand why it's there in the first place. I unchecked the "Show Registration Domain Options" boxes which means I don't want them to show up. So, why then does it have the following above the payment box?
Register a New Domain
Domain thisorthatdomain.com
And where does it get the domain name that it's putting in there? This is confusing to the buyer.
If I wanted to bill a company for, say, 10 hours of accounting work, then why would there be any reference to a domain? This seems like a bug to me. I shouldn't have to start modifying the code to take out something that shouldn't be there.