Converting stereo to mono

I’m a newbie and trying to find a way to convert a stereo .wav track to a mono .wav track. So far I haven’t succeeded. How can I do it?

I can’t recall if previous versions had it, but 1.3x has a “Stereo to Mono” option in the “Track” drop-down menu.

Thanks, I just upgraded to 1.3 and found the function. 1.2.6 didn’t have a “Track” menu at all.