Just copy the game to your memory sticks ISO folder and run custom firmware. For info on how to mod your psp use this link http://www.psp-hacks.com/forums/f118/idiots-guide-to-building-a-magic-memory-stick-t214330/post1039148.html
Death, Jr. embarks with his friends on a school fieldtrip to the local museum. When the group sneaks away to explore on their own, they unwittingly unleash an ancient evil force from a mysterious locked box. Facing near insurmountable odds and the threat of being grounded and sent to military school, Death, Jr. and his pals must fight hoards of demons and their wicked master Moloch through the museum and surrounding town before anyone else finds out.