If you're puller has two tangental threaded holes, I'd grind a notch on 2 sides of the bearing stub, slip the puller over the stub, tighten 2 screws into the grooves and pull. To me, that's a little easier than drilling. If the bearing stub has a 3/8" fine thread hole in the end I'd screw in a 5/8-3/8 NF adapter and pull it out. (Any roller shaft, not just water-pump bearings can be removed like that) Minute 4:30 of the following video
http://www.youtube.com/watch?v=HUzEJ5GI ... e=youtu.beIf the bearing guts come out and leave the outer race (I assume that's what you're calling the "ring") in the roller, this is the procedure I use...
http://www.youtube.com/watch?v=ZBzVd-b5ZYE