Place ham in a very large container; cover with cold water. Soak h am overnight. Pour off water, and scrub ham thoroughly with a stiff brush . Rinse.
Place ham and water to cover in a large Dutch oven. Bring to a boil ; reduce heat. Cover; simmer 4 1/2 to 5 hours.
Remove ham, and set aside to cool. Discard skin from ham. Place ham, fat side up, in a shallow roasting pan. Score fat in a diamond pattern. Bake at 350° for 30 minutes or until lightly browned. Remove from oven. Cover; chill in refrigerator overnight. Cut into thin slices to serve.