If it’s registered here, you can change the nameserver entries in the Panel under Domains -> Manage Registrations and then click on that domain. On the next screen, you can modify the WHOIS info to use those two name servers you posted.
The site any anything else associated with that domain name (except the actual registration) will be handled by VistaPrint. It’s half of a transfer. You’re just transferring hosting (where all the files are), but not the Registration (ownership).