No, not the axle lock, the right rear hub nut that keeps the hub on the axle. The sprocket won't come off unless I remove the hub.

 

Try an impact wrench. If you don't have an air compressor and impact wrench, ask around for an automotive shop if they will zip it off for ya real quick. They shouldn't charge much, if anything.

If you can afford it, I would highly recomend an impact wrench and at least a 5.5HP air compressor with a 20 gallon tank.

Good luck,
CRT_Leech