1. You will receive a premium key like this: 719ftdqh0j6qxxxxx
2. You should be log in : www.kingfiles.net
( If you haven't account at www.kingfiles.net , you just need to sign up )
3. Make sure you are logged in. Then access this link: http://www.kingfiles.net/?op=my_account
4. Paste your Premium key in "Apply Premium Key:" and click Apply to proceed.