Well, Loki caught on faster than Sam. Basically, whenever I took them out AND any time they went near the door, I would take their paw and ring the bell with it (and get all happy!) and say OUTSIDE! and immediately open the door, let them out and run out there with a treat! The key is repetition. Get into a routine. Loki was ringing the bell within a week, and he stopped having accidents as soon as we got the bell because he had been trying to tell us he just didn't know how. Sam on the other hand was more like Lexie, she would just pee anywhere. It took her a month or two to catch on, but then one day she just started ringing it and she has been since. We threw a little "Sam rang the bell!!!" party. Now she rings it for water and attention too, but as long as she rings it rather than peeing on the floor, it's OK. The way to cut down on the ringing for everything is that when they ring the bell, you send them outside. Every time. Even if they just went out. They learn that bell=potty outside ONLY!
The Tell Bell that I sell actually comes with a training DVD (a low budget, lame, hilarious training DVD) but it does explain what to do.
Also, I would suggest removing the pee pads if you are serious about training them to go outside. Mine go outside all year long and we live in Chicago. Really, you can do it!! Oh and Sammy came to us not trained at almost 1 year old and she is trained now, so it's possible!!!