I had a small video that I wanted to remove the background audio from before uploading to Facebook. You can do this using VLC. Here's how. Open VLC and then go to Media (top left hand corner) then Convert/Save… or press on Ctrl + R.
In the Open Media box that opens click on the +Add... button or just drag and drop your video to the File selection window.
Then click on the Convert / Save button towards the bottom.
In the Profile section click on the video format you want. Then click on the wrench symbol.
Then in the tabs across the top click on Encapsulation - click on the video format equal to your selected profile but usually this is automatic.
Then click on the Video codec tab and click on Keep original video track.
Then in the Audio codec tab uncheck Audio and the click on Save.
Back to the Convert window if you haven't chosen where to save the file yet click on Browse then find the folder you want to save the file to. Then click on Start.
You'll get a blue progress line at the bottom of VLC. Let it finish. And that's it.