Question About Music Removal

So, I am working on a few projects, and I have come to a stage where I have to remove the music from a few scenes in the OT. I have the soundtracks from all of the films. I have looked at a few tutorials on removing music using Audacity, but none of my attempts have been that successful. Does anyone here know of any reliable program/method I can use to pull this off?

Prepare an intermeriatary stereo file with channels:
L: has soundtrack
R: has music synced to soundtrack

THEN all you nneed is an FFT imager on that intermediatary.

Try Audition’s Center Chnnel Extractor, or try adding QuikQuak Mashtactic to Audition for a moore visual approach.

EDIT: Also maybe http://blog.wavosaur.com/extract-vocals-from-song-with-kn0ck0ut-vst/