97 civic, manual

i'm replacing the drivers side half shaft, and I cannot get the castle bolt off. the bolt from the ball joint is merely rotating with it.

I've even gone out and bought a 600 lb/ft impact wrench and the bolt/castle nut still turn in unison. I tried putting a jack up underneath on the bolt to apply some pressure to it, that didn't work either!

Surely someone else has had this problem... any tips?

 

Put a jack under the lower control arm. Also put a block of wood between the upper control arm and the fender so the steering knuckle can't move up. This way you will force the ball joint shaft back into the hole so it won't turn. Then unscrew the nut.