You don't say which editor U are using fijberto

If I understand your problem correctly, you've got a video track and an audio track and they're kinda stuck together; what you do to one, happens to the other, which is what you would normally want, but not in this case.

In Vegas, the answer is simple. Click on the video track (the track title bit on the left not the clip on the time line, and press delete. The video track disappears leaving the audio track.

In media studio, I seem to remember that it's not so simple I seem to remember. Been a long time since I used it. Don't have it installed now. I think that I used to use 'replace video' to, um, replace the video with something else. That way the link was broken and it could be deleted.

No doubt some one here will come up with a better solution soon.

Go with that.

Rgds