Unloading a track from a deck.

This may sound like a really stupid question, but how do I unload a track from a deck so that its empty?
Also, in trying to figure out how to do this I found the hidden transposer, which has made harmonic mixing a world easier for me...
Also, in trying to figure out how to do this I found the hidden transposer, which has made harmonic mixing a world easier for me...