I have had to do this more than a few times and I have tried the slide hammer and a special tool that screws into the bearing with a grease zerk on it to hydraulic it out. Limited success and serious frustration with both. The easiest thing I have found (don't laugh it works) is to pack it with wet toilet paper and then hammer it in with a round metal rod. Its not as messy as the grease method and the TP doesnt have a tendancy to sneak out around the rod if its a little too small.
And DO remove the flywheel and change the rear main while the motor is out. It IS leaking.