Edit lower channel only

I am running Audacity 2.1;
I would search the forum, but to be honest I don’t know the correct works to describe what I need.
I have a short section of music with voice. I want to copy one section of it, and ordinarily that is no problem, just hilight-select everything else and delete it, leaving the section I want.
My problem is that they faded-in a drum/music on the lower channel in the screen (left channel? not sure…) while the singer was finishing the song and fading out on the Right channel. I want to edit that left channel only (the drum music) out, leaving the voice fading to end the song. I tried using the adjustments on the far left of the screen, but everything I did affected the entire section, not just one channel.
If I could select and edit each channel independently, that would do it. But I don’t know how to do that and can’t find exactly what I want in the help files.
Any help is greatly appreciated. Thanks in advance!
Audacity.jpg

To edit the channels separately you need to “split” the stereo track.
See here for details: http://manual.audacityteam.org/man/splitting_and_joining_stereo_tracks.html

Thanks Steve, I will give it a whirl!