Do that and then lay the nut on a flat on your vise and smack each opposing flat with a hammer.
I do this a lot on some of our stuff and it works really well.
If it's a locking type nut it will still break loose with the hammer trick but you still might not get it off if you cant hold the ball.
A big pair of vise grips on the shaft as hard as you can lock them if you don't need to save that part works pretty good.
