Turn the sander upside down so that its sanding pad faces you. Unlock the bars at the front and back of the sander. These hold the sandpaper in place on the sanding pad.
Insert one end of the sandpaper under one of the locking bars. Clamp this bar down to hold the sandpaper in place. Stretch the sandpaper tightly over the sanding pad, then secure that end in place under the other locking bar.
turn the Jitterbug sander back over then plug the air line from the air compressor into the fitting at the back of the sander. To do this, pull back on the locking ring on the air line, slide the open end of the air line over the sander's brass fitting, then release the locking ring.
Hold the base of the sander against the surface to be sanded, then press down on the palm trigger on top of the Jitterbug sander. This will allow the sander to operate.