First, when your track is pulled up, there are usually two tracks to it. If it's stereo, it'll say it already in the box next to the track. If it's already mono, all you need to do is export.
If it is stereo, you want to click the drop-down menu with the track's name in it, and select "Split Stereo Track" This is indicated in the red box:
Next, you need to click the drop-down menu again, but only on the top track. Select "Mono" from the menu, like shown:
After that, you can get rid of the bottom track by clicking the X on it's window. Be sure to keep the top track. Go to the pull-down menu way up at the top, labeled "File" and go down and select the option "Export as Ogg Vorbis" Now all you need to do is simply name your file, and export it to base/data/sounds/music in your Blockland folder. Hope this helps.
And yes, I apologize for that triple post. I'm so used to there being a "modify" button there, I just don't even think about it.
