from Yoshihiro:

hi guyz this tool is here for let you use your original game backup
on CFW 5.50 gen B-2 and 5.03GEn.

What's new ?

Comptibility with 5.03GEn is now complete (or not so far)
Thanxs to Revenge-crew for their patch on my v2 that i use for V3)


how i can use this tool ?
1 :lets go first you need to install the GameZDecryptZ folder in your X:PSP/GAME folder
2 : Open you iso with UMDGEN 4
3 : Go to File>File List>Export
4 : Save it as Filelist.txt
5 : Extract the EBOOT.BIN with UMDGEN4 in PSP_GAME/SYSDIR
6 : put your EBOOT.BIN extracted from UMDGEN PSP_GAME/SYSDIR and put it on root of your memory stick
7 : now you can boot game decrypter now you can press X 5 seconds later it's done :)
8 : connect your usb cable check on root of your memory stick you have a new folder called decryptor
9 : copy the eboot.bin from the decryptor folder inside umdgen
10 : Go to File>File List>Import
11 : Choose Filelist.txt
12 : Select YES to forcing LBAs, then Save
13 : REbuild your ISO.