What is the proper way of removing the keeper from the axle gear?
Are you installing new axle shafts in the rear axle?
The axle gears are usually only removed when the axle is unusable, so it's much easier to cut the axle a short distance from the gear - than you can put the short axle with gear in a press, press the gear further onto the axle until the keepers can be removed, then press out the old axle and the axle gear can be reused on the new axle shaft.
The new axle has to be properly supported when the axle gear is pressed on - I haven't had to do that yet, myself, so I'll let others give their input.
So it's a press fit with the keeper rings used as a stop?
Yes. There's a key also that transmits the tremendous power
Here's an earlier thread with some axle shaft photos: http://www.mtfca.com/discus/messages/50893/77953.html?1231423423
To stabilize the axle and keep it from bending when pushing the gear on the axle I use a piece of 1-1/2" square tubing with 3/16" wall.
I don't have the length handy but it's just short of the length of the axle.