How to make one track play through both channels?

I have a long recording that has some annoying buzz in the right channel. I’d like to delete that channel and play the left one through both channels. In other words, I want to end up with a mono recording that has the previous left channel now playing through both left and right channels.

It seems like it should be easy to do, but I can’t figure out. Can someone tell me how to do this?

Thanks.

From the Audio Track Dropdown Menu, choose “Split Stereo to Mono”
Delete the track with the noise using the Track Close button.
– Bill

So simple… thanks!