I had one that was in a really tight spot once. I ended up making a sacrificial tool out of a short piece of 1/4" flat bar. I drilled a 1/2" hole to go over the pin and drilled and tapped a 1/4" hole on either side to push on the bell surface. Then I just welded the tool to the pin and screwed the 1/4" bolts in a little at a time for each and it pulled right out.
Since you've got access to the back, just heat it up a little and tap it out. It should come out easy.