Format the FW drive on your Mac first, as native OS X, don't do journaled or any of that stuff just regular Mac OS X format.
Buy this program
Mediafour | MacDrive
You will see everything on the Mac FW drive when you plug it into your PC, and you can write to it. Even run sessions off of it.
It's buggy software, and don't use DAEMON Tools with it, it makes things really bad. But this is what you want, I'm sure there's other programs but this works perfectly for me. Even sample libraries. Even DMG files.