M.
You just have to take it away completely. He is going to be a terror for a few days, but eventually he won't miss it. He might have to cry himself to sleep. It usually takes 4 nights and it is rough. I did it for my daughter with the bottle at 1 year so I am sure it will be much more difficult to do it at 3 years. I took the pacifier away from her when she was 5 months old because she was using it less and I saw the opportunity. I know I can't really compare, since my daughter was younger. Good Luck!