I downloaded the correct files and followed the readme.

1. copy UPDATE folder at ms0:/PSP/GAME/.
2. Put 6.38 official update at ms0:/PSP/GAME/UPDATE/638.PBP .
3. Run installer from xmb.

I did exactly that on OFW 6.38 and it tells me game can't be started. I don't know what to do at this point. I'm not sure if I was even supposed to go to 6.38 OFW in the first place. Any help would be appreciated.