How to Fix PSP 6.20 Games on Custom Firmware
Of course, there are methods to manually patch your games (UMDGen 4.0, etc), but these are rather complicated, especially when compared to the ease of Eboot Exchange. Another method to patch recent games is with the use of ISO Tool 1.51. Not only will it patch 6.20 games to work on the recent custom firmwares, but it does it right on the PSP: no PC required!