Soak ham in cold water overnight. Preheat oven to 500 degrees. Put ham in pan. Add 6 cups water and cover tightly. Cook 25 minutes. Turn oven off. Let stand 3 hours. Again preheat oven to 500 degrees and cook 25 minutes. Let stand 3 hours. Then open oven door. DO NOT OPEN OVEN DOOR UNTIL PROCESS IS COMPLETED.