Humm, had the same question yesturday, til I dead a bit more.
This is What you do:
1) Download The Patch
2) Put in Flyff Folder
3) Download Hamachi
4) Connect To their Hamachi network Flyff008/1234
5) Go to this page http://5.75.112.10/register.php and register your account.
6) Once you register, stay on Hamachi, this page helps you with any DP items you want or Buffs!!
7) Now you are set to play Flyff4Faith!!
Good Luck to you.