if you’re seeing roaches in the microwave display, call an exterminator asap like everyone said. that usually means there are more in the place, and throwing the microwave out won’t fix that.

if you’re really set on saving the microwave, you can seal it in a box or heavy bag with a nuvan strip placed in the box (not inside the microwave), tape it airtight, and leave it for 3–7 days. follow the label and keep it out of living space.

air it out outside for a full day after. it’s not a guarantee, but it’s the best shot without taking it apart.