i have cut down several. its labor intensive. the best cutting tool i have found is a sawsall with a special blade that you make yourself.
i make a jig for the lug height. usually stock aluminum tubing to match. for the sawsall, i use a "bi-metal" style blade just because of the blades shape. i take these blades to the bench grinder and actually grind a near knife edge to the backside of the blade, not the edge with the saw teeth.
clamp your jig or guide to the track and run the sawsall blade across it. your good for about 5 or six sets of lugs depending on your sharpening skills. onece it becomes harder to cut, resharpen it on the grinder.
i usually run 2 or 3 blades to cut the time down as they do heat up in both the cutting and sharpening process, so you always have a cool blade at the ready.
for our riding out here i have found that a bit of an uneven edge on the track lugs actually give a traction advantage. not concerned with weight or balance for deep snow tracks, your results for a trail track may require more accuracy.
if you really want to get creative, you can v-notch the lugs. this takes even more time and i just use a utility knife for this application. wish there was a paper punch style tool for the vees.