L.W.
I broke my son from his bottle at about 12mo. Once it no longer serves it's purpose, why let them have it?? What I did was to just throw the bottles away IN FRONT OF HIM, and tell him that his bottles are gone gone now. Let him see you throw them away so that he KNOWS they are gone. My son asked a few times, but after that..smooth sailing! The longer you wait, the harder it'll be to get rid of it:D Hope this helps!