Doesn't work in this case as the bolt doesn't come throught the cup so there's nothing to push through. Just pry them apart and you're dandy.

 

If you have the assembly off but still all together an easy way is to loosen off the nut, rest the outer part of the joint on the back of your vice or other suitable solid object and strike the outer section on its side with a reasonably heavy hammer (up to 2-3 Pound) this will spring the taper slightly and cause the taper pin to pop out without any damage to either part.
Believe me even truck steering ball joints will separate using this method but with 4-5 pound hammer instead.
Just make sure you leave the loosened nut on the pin as they spring apart very quickly.
Good luck
JK

 

Good stuff JK.
Sometimes it IS the size of the hammer. Gotta love old school

And yes, back for now.
Curmudgeon's are hard to remove......