This is how we night weaned (although she is back to nursing at night), and we're going to try again starting tonight. It worked before but somehow we got back to waking multiple times. If it wasn't time for her to eat yet, we would just let her cry, or DH would go in and try to put her back to sleep (which sometimes worked). There are a lot of tears and not a lot of sleep when you first start the process, but I think most babies respond quickly to this style of night weaning. Be sure to also keep track of how long you're feeding him instead of the volume - for example:
Day 1: Nurse for 7 minutes every 3 hrs
Day 2: Nurse for 6 minutes every 3.5 hrs
and so on...that way he is getting used to taking less and less milk at night.