Suffolk county, NY: how do I file a Petition to enforce the sale of my Marital property

My Ex wife is taking me to court on Oct 30th to collect 1/2 of the cost for my sons college education as agreed in our divorce stipulation.. I am on SSDI and cannot pay it. There is also a section in the divorce stipulation that states she was to sell my marital residence where she currently resides when my son graduated high school in June/2012. I am willing to have the college expenses deducted from my 50% of the net profits from the sale of the house. Based on an appraisal I had done 2 years ago through a local real estate agent the net proceeds of the sale in 2012 was around $250K.. I cannot afford a lawyer until the sale of the house.