Well we are not in NYC - just about the complete opposite in fact, but we coslept with the girl, and she's still in our bed more often than not.
She weaned at about 2.5, and I think she was in her own bed mostly at that point (it is a bit fuzzy because I was also about 3 months pregnant at the time). For the weaning what we did was talk about it then explain there would now be a time limit on the nursing. At first she could only nurse as long as it took me to sing her favorite snuggling song, then it was to a count of 10. That worked really well - finally it is as if she decided it wasn't worth it any more.
Plus pregnancy changes breastmilk so maybe I can't take any credit at all!
I'm not sure how to co-sleep and night wean. I think most moms find it quite hard. But maybe the song thing would work for you?