Cut out section where inserts will be placed. Place masking tape on edge of mounting surface and inserts.
Use wood sticks and hot glue to fix the inserts in the correct position.
Grind the edges between the seam on both the part and insert with 40 to 80 grit sandpaper. In a container, mix a small portion of resin (around one pint) with 1-2 % hardner (2.5-5cc for every pint). Begin applying small strips of fiberglass matt to the edge of the scoop and roof. Apply a second layer of fiberglass matt to the perimeter of the scoop. 2 - 4 layers are sufficient. Generally you want 4 oz. of matt, so if you are using 1 oz. fiberglass matt you would apply 4 layers, and 2 layers if you use 2 oz. fiberglass matt.
Smooth out the seam using either Bondo, Duraglass, or other body fillers. Body fillers can be purchased at auto supply stores (AutoZone, Walmart, etc.). Sand down the body filler using the following grits in stages: 80 to 180 to 320. The values do not have to be exact, meaning 220 can be used in place of 180. For best result use a sanding block to make sure there are no high or low spots. Follow with primer and paint.
Cut out section where inserts will be placed. 
