Since Evan didn't buy a new roll of film for his camera, I will post some pics for him. It is alot easier to remove the wheel and rim, leave the axle in the trumpet, and do as Evan says.
Is yours a 1955 or 56? Is it on the right side? Seems to be a flaw at the factory. Agco should recall these and fix them all for us! Fat chance eh?
These are pics of a couple I have done the last year or so, and the rusty castle nut is what I used to 'double nut' the new pin- one wasn't broke off, it was unscrewing itself, but you can't retighten it without a split either. A new one is sitting on the 4x4 next to the busted one- near the can of cheap soda. Have fun.