yes you can update them too
http://help.godaddy.com/article/418
Updating Your Contact, Registrant, Administrator, Technical, or Billing Information
To Modify the Information for Your Domain
1. Log in to your Account Manager.
2. In the My Products section, click Manage Domains.
3. Select the domain name(s) for which you want to change the information.
4. Click Contact.
5. To update all of the tabs with the same contact information, select Update all contact types.
or
Go to one of the following tabs, depending on the contact type you want to update:
Registrant
The domain owner.
Admin
The contact who can interact with the registry or registrar for the domain owner.
Technical
The contact who manages the domain.
Billing
The contact who receives invoices for domain registration fees.
6. Complete the following information:
First Name and Last Name
The contact's first and last name.
(Optional) Organization
The organization with which the contact is affiliated.
Address 1 and 2, City, State, Postal Code
The contact's street address, city, state, and ZIP Code.
Country
The country in which the contact resides.
Phone
The contact's phone number.
(Optional) Fax
The contact's fax number.
Email
The contact's email address.
7. If you enter a company name as part of the legal domain registrant and agree that the company is the legal registrant, select I certify that the specified organization....
8. If you changed the registrant name and agree to the Domain Name Change Registrant Agreement, select For security purposes I authorize....
9. Click OK.
