Since the domain has been transferred to DreamHost now, you can do it through our panel under the Domain Registrations tab:
 Click the domain name in the list.
 Click the “Modify WHOIS info” button at the bottom of the WHOIS information.
 In the dropdown menu at the top of the page, select “Nameserver” (last item in the list).
 Switch the radio buttons to “Use DreamHost’s nameservers” and click “Update”.