Pepperoni is a cured sausage product, typically made of pork or beef. Like most other sausage, pepperoni has a casing which helps the meat retain its cylindrical form. Some pepperoni casings are thin and edible, but others can be thick and unpleasant to chew. When the casing is too thick to eat, it can easily be peeled away from the meat. Since the casing essentially acts as a coat, and is put on after the cooking process, there should be no problem with peeling it off.
Lay the pepperoni on a clean cutting board.
Hold the pepperoni firmly with your less dominant hand. Do not, however, hold it so tight that you crush it.
Grab a paring knife with your dominant hand. Carefully slice the casing, starting at one end and working your way to the other. Keep in mind that pepperoni casing is generally thin, so it takes little pressure to cut through it.
Hold the pepperoni with the cut side facing down. Spread the casing apart and push out the pepperoni.
Store the pepperoni in a sealed container if you don't use it all at once.