First off, are you sure you have a Davis wind scoop, or do you have a Breeze Booster. The Breeze Booster is self supporting. If you indeed have a wind scoop, see if there is a pocket at the bottom back of the scoop to insert the dowel into. If found get a dowel longer then your hatch opening, insert into the pocket and dowel will act as the stop. There should be a grommet at the end of each of the wings. Screw in a couple of cup hooks, or the like, into the hatch trim and hook the wings via the grommets into the cup hooks. The top of the scoop is usually held up with the jib halyard or a line to the head stay .
The value of the self supporting Breeze Booster is obvious if you find you need to buy something new.
Enjoy