It took a little bit with my kids too. It is hard. With my older one I told him those were for babies and his baby brother needed them and that worked but he was old enough to understand words. My younger one chewed them all and they broke so I just told him they were broken. He didn't like it when they had holes in them and he lost interest. But my kids were older, a 5 month old is not developmentally going to compute other than give me my pacifier!
Why so soon? The National Pediatric Association actually recommends pacifier use until at least 6 months old to help prevent SIDS.
Also, babies do usually respond well to pacifiers because of the sucking; it is a comfrot thing and a stimulant. It is actually a good thing for their brain because of the stimulation.
Anyways, your baby is still little, maybe waiting until he is at least 1 would be better.
Maybe just cold turkey but he is so young.......
A baby this age I don't know what I would recommend, ask your pediatrician.
Good luck and let us know how it turns out.