PS2 DVD Editing, Nero

[burnmp3s]

The game I am trying to do this with is THPS3, and I've edited the music.wad file already. I have the CD/DVD-ROM generator, but it won't work with my burner (Pioneer A04). I can get what I want to burn in a .nri file in Nero, but this isn't in a format the PS2 can read. I also have a .nrg file for the original, but I don't know how to change it to have the new .wad file in it.