I would wean in that case or else cut it down to one short session a day and no more than that (depends on how you think he'll do with the process - some kids do better with one session left for them to drop on their own, others do better with mom making a hard and fast decision about weaning and sticking to it).
How to handle it is to talk with him matter of factly and say that once X day comes (pick one on the calendar) that will be the last day for nursing and instead he will get a special toy (or something else he's been wanting that can mark this as a significant milestone).
He will most likely have conflicting feelings about it, be sad at times, ask to nurse again, and even be angry. Parent him through that - reflect his feelings, offer cuddles, redirect him to other activities, and above all appear confident about the change and don't waffle - stick to the weaning that you previously decided on IMO.
Mom of 4: Boy (10), Girl (7), Boy (4), Girl (2)