We had to do this with our eldest.. he was just around 2 and was very addicted to his bottle and dummy. i put water only in the bottle to begin with but after i left the room i got a bottle thrown at my head so we just said ;no Ethan you are a big boy now.. bottles are for little babies.. and he took about a week before he stopped asking for it...

He still asked after it from time to time when he was tired but we just changed his routine and added smething new instead of the bottle..