Assuming you have bought the 3rd part modules with the rights to use on as many DNN install as you want:
1 - Copy the site files and backup the database;
2 - Restore them both on the new location - I will assume you know that you have to commission a new site by using something like IIS or if you use a control panel like plesk, you do it there;
3 - Change the PortalAlias table, the URL field to point to the new domain;
4 - Adjust the db access in the web.config file;
That should get you going.