PUT IT ON WHEELS Invest in a hand truck with large pneumatic tires that won’t scratch the bullnose on the treads on the way down. Place the AC on the truck with the grille facing out to prevent it from cracking, and hold it in place tightly with rope or ratcheting straps as you walk it down.
OR BUILD A SLED Grab a piece of inch-thick plywood that’s just wider than the AC unit and about 40 inches long. Wrap the bottom and the front and back edges with carpet scrap, clamped in place with 2×4 cleats and screws. Thread a ratcheting strap between the plywood and carpet, then place the AC with the metal cover resting against the front cleat, and tighten the strap. Center a 3⁄8-inch-diameter eyebolt in the rear cleat and knot a nylon rope around it. Wrap the rope around your back, and with your dominant hand feed the line to your other hand, guiding the sled down the stairs, as shown.