Go to one corner edge of the carpet where it is tucked down against the walls in the room.
Grasp the corner edge with the tips of your fingers or pliers and pull it back toward you. Pull up the carpet by hand along the wall off the carpet tacking, the whole way around the room. The carpet should be free and no longer be stretched tightly over the spiked floor tacking around the edges of the room.
Place a power stretcher at one end of the room and slide the telescopic handle out until both sides of the carpet stretcher are near the walls on opposite sides.
Push down on the handle on one side of the power stretcher, then go to the opposite end and press the other handle down; the carpet will stretch, becoming taut and lay flat against the floor.
Tuck the ends of the carpet between the tacking and the walls with a carpet tucker around the entire room. The back of the carpet will become attached to the spiked tacking on the floor, keeping it in place.
Go around the edges of the room and cut off any excess carpet with a utility knife. Dispose of the excess strips.
Pull the handles up on the power stretcher to relax the device, then collapse the telescopic handle to finish.