How do you wean 14-week old from the pacifier?

My baby sometimes needs to pacifier to get to sleep, but not always. He mainly needs it to calm down if he is all worked up. I'd prefer it if he sucked his thumb instead but he still hasn't got the hand of that. We swaddle him at night but are going to start leaving his arms out in the hope that he will find his thumb. Any ideas on how to wean him off the pacifier?