I agree with Educator and Tool guy but, if screws are a problem there is an alternative. Wal-Mart has foam and felt in a roll with sticky on the back. Close the door with you on the side that the door stops against (it is called Stop), unroll the strip and place the edge of it against the door and stick it to the stop. Then you can roll a towell up and lay it at the bottom of the door and you are sealed. It might even be a little less expensive.