Ken
Not quite as easy as the principle suggests. First the original screws have to come out cleanly. Protect the front wing in case the door swings forwards. Try both checks on the first side because they will fit slightly different. One of mine stands a bit proud when the door is closed. The tension/stiffness is important and adjusted by the two vertical nuts&bolts. Not tight enough and it won't hold the door in position, and too tight and it will strain the fasteners. Trial & error will get you there!!
I think one of Frank's screws had been hammered in and had bent.
