Preheat the oven to 275 to 300°F.

Line the baking plate with aluminum foil. This will help keep the ham moist. 

Wrap your ham tightly with aluminum foil or its original foil wrapper. 

Add a tablespoon of water to the bottom of the rimmed baking plate. This will prevent the meat from drying out. 

Heat your ham. Note: For every pound of ham, you need to warm a whole ham up for about 10 minutes. 

Remove from the oven and serve.