First you need to goto the linkshell community and put your character data in there, once this is done, register for an account here at guildwork.

Add your character, it will ask you to verify your character with a strange code, go into the linkshell community and go to your own profile, there is a box that says "comment" copy/paste the phrase. :D and your done. It should put you in the linkshell roster at that time.