My wife and my daughter (Married) bought a vacant land. Both of them paid initial 10% deposit and balance amount financed by the bank. The home loan is on all 4 names (My wife, My daughter, her husband & I). My house is given as security. After settlement my daughter and husband were not in a position to pay the monthly mortgage amount as her husband lost the job. My daughter and her husband requested us to sell the land or do whatever it takes to release them from this commitment. They said they would be happy if they can get their deposit back. Hence I agreed to take over and sell the land. I couldn’t sell the land, as it is hence I decided to put two houses on that land and sub divide and sell the land with plans and permit. I have spent considerable amount of money and time for architect and town planning to design and all the approvals. Town planning took about 15 months and I am on the verge of proceeding to subdivision process, which expected to take 6 months. Meanwhile our relationship with our daughter and her husband went sour. Now they are demanding their share of profit from the sale process to sign the required documents. How I go about it under property law?