Ford Repair: main bearing removal, ford bronco ii, 1988 ford bronco

Question
I have a 1988 Ford Bronco II with a 2.9 liter V6. I am trying to remove and replace the main and rod bearings without removing the engine. I tried to unbolt the exhuast so I could pull the motor but a couple of the bolts are rounded so engine removal is not really an option. Is there a trick to getting the old bearings out without dropping the crank? Right now the oil pan and pump are out and all the caps are loose but I can't seem to get that top bearing to slide out.

Answer
I suppose you could tap them out with a small punch and get them to spin around the crank untill you can pull them out.  I would never do a job this way though, i could see changing a rod and piston with the engine still in the car but to change the bearing, i could not see doing a good job without removing the engine.