Depends on how its done.

First check the audio tracks and see if there is one with a voice over and one with regular audio - if so, easy! Reencode and drop the unneeded track.

If not.... Youre going to have a rough time, you'd be better off trying to find just the audio and aligning it.

Edit: or another copy of the show obviously.

The handy bit would be if you could find a crappy quality version, you can still pull the audio from there and align it with your copy. It may not be great audio and still require some degree of effort to sync properly with the video, but it would be a much more realistic effort than trying to remove speech from the same track.

I know in vlc you can just go into 'audio' and choose audio tracks. Some tjings have more than one. But you can also just turn it off. But also you can just turn volume off.

Not a good one, what show is it?

Watch with subs?