Preheat oven to 350 degrees F. Line the bottom of a roasting pan with foil. Place a roasting rack into the pan. Place ham on the roasting rack. Scour the top of the ham 1/4-inch deep in a diamond shape. Cover lightly with foil and bake for 40 minutes.
Meanwhile, in a medium bowl, mix the brown sugar, mustard, vinegar and Worchestershire sauce.
Remove ham from oven and brush with 3/4 of the glaze. Cover with foil and bake for 30 minutes.
Brush with remaining glaze and bake another 30 minutes. Allow to sit for 10 minutes then slice.
***The standard for smoked ham is 10 minutes per pound. If you have a smaller or larger ham, used these standards to adjust your baking time. The ham is already cooked so you are simply heating it through.
