If your child has been using a pacifier for self-calming since birth it can be very difficult and even traumatic to wean him off of it cold turkey. I suggest you implement a gradual weaning process of three to four weeks and allow your child to be a part of the process.
Talk with your child about what day the pacifier will be gone for good and mark it on the calendar. Between the day it's announced and the actual day it goes away, allow him only specific times during the day or night when he can use the pacifier. He should have some input into when those times are. This will give him a feeling of control over the situation.
During the weaning process it's important to praise him for the times he can go without the pacifier and cheer him on toward his goal of getting rid of it completely. This is also the time to introduce more appropriate self-calming techniques he can learn such as listening to music, holding a stuffed animal, etc.
Once the day of "Goodbye Pacifier "arrives, there should be a special party complete with a small reward for having achieved his goal.