Removing the audio from an mpeg2

I've been trying to remove the audio from a few mpeg2 files so i can edit them (the DVD they were ripped from only had 5.1 surround sound, and the program I'm using doesn't support surround sound), but trying to find a program that actually does that for mpeg2's wasn't very successful. Converting it to another format is out of the question, I'm trying to keep the quality as high as possible. If anyone has any idea of how to do it without messing with the video at all, that'd really help.

 

Try 'ReJig'.
Select the stream and demux.

http://www.afterdawn.com/software/video_software/video_tools/rejig.cfm

 

You might also give this a shot.

http://www.aoamedia.com/audioextractor.htm