Preheat the oven to 325°F
Remove the ham from its packaging
Place the ham cut-side down in a roasting pan
Add a small amount of water to the bottom of the pan
Cover the ham tightly with foil
Heat until warmed through, about 10 to 15 minutes per pound
Remove the foil during the last 15 to 20 minutes if glazing
Brush on glaze if desired
Return to the oven until the glaze is set
Check that the internal temperature reaches 140°F
Let the ham rest for 10 to 15 minutes before slicing