Step 2 : This is the page you will see when logged in the domain management panel
To update the Admin contact details, click on the highlighted logo appearing below the "Modify Admin Contact" as shown in the above screen shot.
In the editor you need to enter the contact id if you already own one or you need to enter new admin contact information
Step 3 : This is the page you will see
Modify Administrative Contact Information
The same procedure applies for both the technical & billing contact information updation.