I don't have experience with this (my dd nursed until 18 mths but slept in her crib) but I do have 2 friends that had the same issue- one bf and co-slept until her ds was 3 and the other bf and co-slept with her dd until her daughter was...4.5! In both cases I remember they told me the addressed the co-sleeping part first, before the bfing to sleep. So, I would maybe try to nurse him in his own room, put him in his crib, lay down on the floor by his crib to sleep beside him (blow up bed or sleeping bag, or something so you're comfortable). I would get him used to his own crib like this first, still nurse him at his request, until he's used to sleeping in his crib. Once he's fine in his crib, start removing yourself from the room, move your sleeping area further and further away from his crib until you are out the door. Then, deal with the night bfing, maybe visit the bfing board for ideas- I've heard of everything from offering water instead of a bf, or shortening the time on the breast. You might even find that once he's sleeping in his own crib he may not wake to bf.
