PS2 talk

So I was finnaly able to put PS2 iso's on hdd thanks to USB converter og right said i'm going to put PS2 iso's on hdd, right now i have download couple of Å PS2 isos and i'm going to download more tomorrow.
Then i'm going to put PS2 iso's on hdd and then insert HDD in PS2 and play games i have download.
I'm really looking forward to it.

How can i cheat on games i have on Hdd?