I actually rented a 'pilot bearing puller' from a local tool rental place a few years back. It's a slide puller type affair, with three fingers with small hooks on the ends that slide inside the pilot bearing, check around in you area, great tool.
The grease method I've used before with some success. Just pack the area behind the pilot bearing full with grease. I used a wooden dowel that fit pretty tight in the hole and drove it in with a hammar and the bearing spit right out, well sometimes. Other time I had to rent the tool.
