Way to go! I taught mine some time ago, but I stopped because he now shows me when he wants to go outside by walking towards me and going to the door several times.
The way I taught him how to ring the bell was: I put a Christmas ornament bell on the handle of the entrance door, and everytime I would take him outside to make potty I would ring the bell with his paws. I did that until he would ring it on his own, so he knew that everytime he rang the bell I would take him outside
