You must be logged into your account to assign a domain to a website and we also recommend that you have published your site.
1. Once logged in you will be taken to your Account Dashboard,
2. Click on Domains under Manage Sites
3. Your purchased domain name will be displayed on this page, Click on Manage in the domain management section that appears next to the domain name you wish to assign to your website.
4. Now you will be shown an Overview of your domain details, to assign the domain to a website click Edit next to Assigned.
5. From the drop down box that appears, select the website that you want to assign your domain to.
6. Now click Set.