hey guys i have an unmodded PS2...you need to have something to be able to get games saves to and from your mem card...if you can do that, you should be able to get the hack to work...its called a PS2 mem card exploit
as for a modded PS2 i have no idea...
the things you need for the exploit to work is a fat PS2, old PS1 game (that works as the trigger disc), MEM card, and some way to communicate with your mem card ie: xport, sharkport, max drive...something like that..if you have all that its just a matter of downloading a few tools and creating a game save to put onto your MC...