Remove ham from refrigerator about 3 1/2 hrs before serving time to let it come to room temperature. If upper surface is covered with a rind, pull it away with your fingers. With a thin sharp knife, slice away the thick layer of fat beneath the rind til only about 1/4 inch remains. Score a diamond pattern about 1/2 inch deep into the upper surface of the ham with the knife. Position a rack in lower third of oven and preheat oven to 325. Set ham in large shallow baking dish or jelly roll pan. Put it on the oven rack, add 1 cup water to the pan and bake for 1 1/2 hours. Meanwhile, in small pan over low heat, melt jalapeno jelly. pour off water from roasting pan, replace it with orange juice land continue to bake the ham basting every 10 minutes, first with melted jalapeno jelly and then with the accumulated juices from the pan, til it’s golden brown and shiny and is fully heated through, about 40 minutes. Let ham rest at least 20 minutes before carving. Serve warm or cool. Serves 12, with leftovers.