Butch drill the screw holes out for the size you want a bolt and nut. Glue a piece of wire to the washer (fender size ) and also to the nut. Fish wire up thru 3/4 hole for both. Stick plate back and put marine Tex on bottom to floor. Stick threaded screw in hole and use wire to place washer and nut on screw and tighten. Put marine Tex on other screw and retightened. If you can't figure this out call me.