Please do a search first next time. But here you go:
Thread 219109 (You can select the D2 OST individually on Mega)
Unfortunately the official release ommits many tracks that are in the game. I don't think that there is a proper game rip around yet.
Currently 'Attempting' a custom rip.... think i have found all the music in the data files but wont know till i have sorted them out! Watch this space -----> <------ (not really!)