PSP - 5.50 How to Hack Help?

Hi, I have a Phat 5.50 PSP, and my friend "apparently" hacked it, but I think he just bought Crisis Core the game I wanted online, and placed it on the PSP.So I know there are two options,1) Pandora2) ChickhenCan someone please help me find the right Chickhen and a How to?

As far as I know, Chickhen doesn't work for 5.50.