It doesn't seem hard to do. The program just needs the .elf file and you just tell button you want to replace with the other. HOWEVER its purely better for the PCXS2 b/c periodically the button won't read on the PS2, even if you're holding the button down. Then again I'm not sure if that depends on the cheat program, I am using SM Coder also game disc I'm using is a backup not an original (can't find my original).
I've imputed this into SwapMagic Coder on the PS2, and I have to say it works beautifully. The only strange thing I found is that R3 also works as an attack/select button too.
*edit: I'm an idiot. That's how it's supposed to work. ಠ_ಠ
