1. Please log into your Xubster account first: https://xubster.com/login.html
( If you don't have a Xubster account, please register a free account )
2. You receive a activation code / premium key like this: 509sswunjmzs4dxaj that you can apply here https://xubster.com/?op=my_account
3. Enter activation code / Premium key in field with description "Apply Premium Key" and click "Apply" button