Add/Remove audio to QT

Hi,

I was hoping that someone might be able to help me. I'm not a video editor and what I've learnt has come from self teaching via youtube videos and forum posts and I've got a bit stumped.

I've working on a microbudget film and we were sent (by a reputable firm) the finished footage as a QT with 1 audio sound track and 8 channels - ch1-6 are 5.1, ch7-8 are stereo. (annoyingly unlabelled inside the QT)

We need to send it to someone new but with only the stereo and a newly created M&E (no dialogue) audio. I have the audio files but I'm struggling with this process.

I know in QT7pro you can delete and add audio files, but these create new audio soundtracks - so in this case it would be soundtrack 1:stereo and sountrack 2:M&E. As we weren't sent it like this in the first place I'm hesitant that that is the right answer...

Using FCP7 for exporting multiple channels of audio, I also end up with multiple soundtracks as above. If this is the way it should be, I'm wondering why a reputable company sent us the film with the audio split over 8 channels?

Does anyone have any clue as to what the correct way I should be creating this is? I really appreciate any help you might have!

Thank you very much!