you go to your bedroom first.  you find your heaviest bucket of toys and prop the bucket on top of the door.  there's just enough room to squeeze thru the rigged door.  you enter your parent's room and see a round ball with "16" etched on the side.  this'll work!  you adjust the entry door and lift the bowling ball up to the top.  there must be a nice divot on the top edge; the bowling ball rests in place.