Legal Question in Real Estate Law in New York

That's a very unfortunate situation. Unless one person can refinance the mortgage in their name, and the other is willing to move out, the only other option would be to sell the house. Hopefully the owners will agree in a friendly way and go their separate ways. If not, the court has to get involved and force the sale of the house. The bank has to get paid one way or the other. There's no way to 'get out of the mortgage'. Both people signed their names on the loan and there are obligations and consequences for that.

Good luck.