how to get hinge back plate that has fallen?

find what holds the outer door gasket in position usually thin wire/spring band and remove it, peel off the gasket on the hinge side, WARNING put a towel on the metal lip edge, then carefully put hand gently, slowly, through the hole (gap has sharp edges hence the towel) and recover the back plate.
Hold the back plate in position while rehanging the door, refit the gasket onto the lip, refit the wire band.

wirecutterman
June 2009