Insert the flat-head screwdriver into the track channel, using it to loosen any debris that may be present. Use a vacuum to remove all the loosened dirt and debris. Tighten all of the screws in the track channel to the floor and replace all screws that cannot tighten. For dented door tracks, measure a portion of the track that remains intact and cut a plank of scrap wood to that measurement. Insert it into the undamaged portion of the track to be sure it is the correct size. Use a hammer to gently slide the wood towards the dented area, opening up the dented area so that the door can slide properly.