Hi guys, I know this topic has been covered before, but since the thread is on going I'll post the official Chambers/Siler Lock statement on removing a tumbler.
Never pry it off whether using a screw driver or a tumbler puller. When it breaks, and it will, it will always void the warranty on the part. The tumbler's axle is slim and has a hole drilled in it - thus it will crack and will break if any angled force is applied.
We also don't recommend inserting anything into the screw hole to push it out. Once again if the tumbler has a tight fit to the hammer, as it should, the force being applied to remove it is applied at the bottom of the hole, thus leaving the axle shaft still tight bound in the hammer. The push out pressure it applied in the wrong spot typically resulting in a broken axle.
I can understand using a screw that fits the hole, but if the threads are not a pure fit, you run the risk of buggering the threads.
So, how do we recommend removing one... by setting the lock over an open vise, with the tumbler hanging between the jaws. Then using a punch that rests on the top SQUARE of the axle, not in the hole, hit the punch with a swift whack. This applies the removing force down the through the whole axle shaft and out into the tumbler body. It also avoids any unintentional angled movement. I have taken several photos to demonstrate...
hope this helps...