Need it out as the chassis is going for galvanizing. It seems to be stuck on the interior collar.
My get the wife to stare at it, she makes everything shrink................ 
It will be tight at the bottom. You could do with getting some push or pull on it somehow to load it up, then whack the top about as there is (supposed to be) some play at the top once the bolts are out, once you get it to move you have won, it should edge out if you keep loading it up and moving it side to side, this could take some time.
Sitting it on a jack is agood idea, if you still have enough weight with the engine etc still in?