We gave DS plenty of warning that the day after his second birthday we would put all of the dummys in the bin. He understood that things don't come out of the bin. I reminded him every couple of days or so until the big day. Then on the day after his birthday we packed them all up together and he put them in the bin. He asked for it the next day but we just reminded him they were in the bin. He was really good with it. I do think that for an item like that which provides them with so much comfort it is good to prepare them for the change.