1. You receive Premium key look like: 1479umf0309wj3wxxx

2. You should be log in at https://filemass.net/login.html

(Please register a new Filemass account, if you don't have an account)

3. Access "My Account" to activate your Premium key: https://filemass.net/?op=my_account

Enter Premium key in field with description "Apply Premium Key" and click "Apply" button