All domains are registered to you. You can update the whois details from the client area at http://www.fast2host.com/clientarea.php
Select "My Domains"
Select the chosen domain name and then the "More Options" button
Click the "contact information" button at the bottom of the page.
For a demo visit http://www.fast2host.com/flash/getting_started.html
Please note: Due to API limitations, the above process may not work for .uk domain names. Contact us with the new/updated details, and we will arrange to modify the records at Nominet. If you have received login details from Nominet when you regsitered your domain, you can log in and make the changes yourself.
PLEASE NOTE: Changing the contact information for a .uk domain name does not change ownership of the domain. Ownership transfers can only be carried out direct with Nominet.