Preheat the oven to 350°F
Spread the nachos in a single layer on a baking sheet
Remove any cold toppings like sour cream, guacamole, and lettuce
Cover loosely with foil if you want to reduce drying out
Heat for 5 to 10 minutes until the cheese is melted and the chips are warm
Add fresh cold toppings after reheating
Serve immediately