I've done it twice. If you can get about a quarter inch of separation, then you're almost home free. I put the tops of my fingers facing each other between the gear and the bottom of the frame, then bow up on it, holding it in front of my chest. That's usually good enough to get past the brass ferrule on the swashplate. If the top bearing is stuck, then I suggest the pinion puller tool. It works great so long as the bearing is within about 3/4 inch of the top. For the bottom bearing, you can use a dremel to saw off the shaft at the plastic end and use the pinion puller there, too.

To put bearings back on a rough shaft, I use the pinion puller's blade (only) and a deep-well socket and hammer them on.

Someone suggested a repair method for a bent shaft, and I did it today, and it worked. Put the shaft in a drill chuck and turn on the drill (on slow). Make little adjustments to get it as straight as possible. It's still a little wobbly, but at speed, you can hardly tell. It'll get me by until I can get a new shaft. I tried all night googling to find a titanium one, but no luck.

[Update: here is how to do a titanium shaft][link=http://www.rcgroups.com/forums/showthread.php?t=527017]here[/link]
[Update2: Elektro-RC no longer carries the hardened main shaft, but they referred me to ICare-RC, which does have the[link=http://www.icare-rc.com/maxir_pricelist.htm]Y0319[/link]; and so I ordered the Century AR hub & Y0319 shaft. We shall see... ]