first download these programs that i found then uploaded(copy and paste the links on your search browser if it doesn't work,and i didn't make these files)
http://www.megaupload.com/?d=JW07YVYK>>>UMDGen 4.00
http://www.megaupload.com/?d=FCMYXVZF>>>5.55 & 6.00 Games Decrypter V4
and follow these easy steps to play games on 5.50Gen or 5.00m33
step1:Put the 5.55 & 6.00 Games Decrypter on your memstick like any other homebrew.
Step2:If you are trying to play a game such as disgaea 2 or anything else on a UMD then turn on your psp and go to your vsh menu and put your usb device as UMD disc
Step3: Go to usb mode and copy UMD9660.iso to your desktop(all discs iso file are called UMD9660.iso) and launch UMDGen 4.00
step4:Now that you are on UMDGen look for the game you are about to decyrypt,UMD9660.iso or whatever you named the iso
step5:look for PSP_GAME/SYSDIR and click on it,then copy the eboot.bin onto your desktop
step6: Go to your psp vsh menu and change USB device to your memory stick and copy the Eboot.bin in the root of your memorystick(the root means not to put it on any files such as GAMES,ISO,etc just copy it on your memorystick)
step7:Exit Usb mode and launch the game decrpyter on your psp,you should get a black screen saying *press x to decrypt your eboot.bin* well press it and it wil begin the decyryption.
step8:Now go put your psp into USB mode and look for a new folder that has been created by the application called *DECRYPTOR* and open it.It should contain an EBOOT.BIN file
step9:now launch the UMDGen application and look for the game you were trying to decrypt and look again for the file PSP_GAME/SYSDIR and delete the EBOOT.BIN inside the iso file and replace it with the newly decrypted one and then click SAVE because just clicking the X button won't save.
step10: (finally your almost done)Now that it's saved put the UMD9660.ISO or whatever you were trying to fix on to your psp ISO folder and it should work.
Okay before anyone thinks that i copied this tutorial well i didn't,the original tutorial i found was on www.psp-hacks.com and i simply just tried to make it easier for people to understand just pm me or write your questions down here.