Start getting him used to the idea that when the dummy gets old or broken it will be time to throw it away.

Cold turkey. You’re in for a rough couple of weeks but just stick it out.

One of the downfalls of using a dummy. I have a friend who’s 3 yo still has a dummy all day and night, he won’t quit it. Yet another who just suggested giving it to Santa one Xmas. That worked

Are you able to swap a dummy for another comforter item at all?