Remove all accessories and debris from your fireplace once the fireplace has cooled down.
Vacuum or sweep out the fireplace.
Look inside of the fireplace and locate the damper right above the inside wall.
Remove the four bolts that hold the current damper in place by using a wrench. The damper can be in the open or closed position to access the screws, but it will be easier to remove if the damper is closed. To close the damper, either pull down on the chain connected to the damper and release it once the damper closes, or slide the rod over until the damper is closed.
Turn the damper sideways and pull it out from the fireplace.
Slide the new Vestal fireplace damper up into place.
Insert the four bolts into place, and then tighten them with the wrench.