Got it, tried asking, but didn't get me too far.
I just downloaded Audacity, Linkage: http://audacity.sourceforge.net/
I do use Nero Wave Editor to edit my songs, so I'll start from there.
Once your song if edited, save as whatever format.
Open Audacity, select you whole track (Ctrl + A)
Got to Tracks > Stereo to Mono in the menu bar.
And save as an .ogg file, there you have it. A mono .ogg!