help ripping dvd game
 

i'm trying to backup dvd game to cdr and i have no clue what to do next. problem is there isn't that much movie or sound file i can remove. i have 2 files that seems like taking all the space, DATA.DAT(1.02gb) and NULLDATA(1.04gb). what can i do? can i remove NULLDATA file and replace it with dummy? even doing this, i don't know how to make DATA.DAT smaller. if someone can help me, i would really appreciate it. thanks.

BTW, game i'm trying to backup is Dragon Quest 5 for the ps2. if there is rip kit, please let me know.