If you haven't chosen you domain name
You might have bought a Premium account without yet setting up your domain name. If so, you can set up your domain name now.
How to change my domain name ?
Go to domaine name set up, then click on the "Update my domain name" link.
The process will be explained to you, then you'll have to type your password to proceed with this update of your domain name (which will either cancel your subscription or reduce its duration if you have more than a year of subscription left).
We will cancel your current Premium subscription
Domain names work in an annual way and it's impossible to get one on a shorter period. In order to change your domain name, we need to cancel your current year of Premium subscription.