How to activate Rockfile Premium Voucher:

1. You will receive a Rockfile premium voucher like this: 7999xxdlnd5774la

2. You should be log in : https://rockfile.co/login

( If you haven't account at Rockfile, you just need to sign up: https://rockfile.co/?op=registration )

3. Make sure you are logged in. Then access this link: https://rockfile.co/account

4. Put your voucher code in field "Apply Premium Key", and click on "Apply"