I stuck the wife in the car to stomp on the brake and stuck a 4' pipe on a breaker bar. But, 2 thoughts I have here from what you're describing:

1. Even though an entire new axle assy is only $60, I think grinding the nut off is only going to be the start of your frustrations, meaning if you can't break the nut loose, you are going to play bloody hell getting that shaft out of the hub if this is due to metal corrosion, etc. A lot of folks gotta get medieval on the shaft even without nut issues. I just tossed the half-shaft assy in the trash can and replaced it, so I didn't have to care about dinging up the end of it. But, If you are planning to reuse the axle, then:

2. Read through some of the threads where folks did the CV boot without removing the stub from the hub.