Heat oven to 325°F. Place ham, fat side up, in shallow roasting pan. If necessary, trim fat from ham. Score ham diagonally at 1-inch intervals, cutting about 1/4 inch deep; score in opposite direction to form diamond shapes. Insert meat thermometer so bulb reaches center of thickest part of ham but does not rest in fat or on bone. Bake at 325°F. for 1 hour.