Stay tuned for more PS3 Hacks and PS3 CFW news, follow us on Twitter and be sure to drop by the PS3 Hacks and PS3 Custom Firmware Forums for the latest PlayStation 3 scene updates and homebrew releases!
After installing the game, FTP into your PS3 or access your internal HDD any way you prefer (eg Multiman's file browser)
Go to /dev_hdd0/game/NPUA80636/USRDIR/data/
Move "music" folder to /dev_hdd0/game/NPUA80636/USRDIR/data/gos/
After you done that, you should have 4 folders "dialogs", "movies", "music", "packfiles" inside /dev_hdd0/game/NPUA80636/USRDIR/data/gos/
Have fun playing with epic God of War music