1. Please login into your 1st-Files account first: http://www.1st-files.com/login.html
( If you don't have an account, please register a new account )
2. You will receive a Premium key like this: 8928r7zjwjgutzzzzz , that you can exchange here:
http://www.1st-files.com/?op=my_account
3. Put your Premium key in "Apply Premium Key:" , and click on "Apply"