I should have taken an extra photo before this one. In order to mount the new light, you need to put the base plate of the new light against the roof support, and mark where the three holes are to be drilled. Drill the holes mount the base along the edge where two screws go, then put the chrome cover on and put in the last screw. Finally, there's another short screw to hold the other side of the chrome cover on - this last screw goes into a plastic clip on the base plate. Clear as mud?
