Heard back from the factory regarding my questions about the lighting install (I emailed them).

The wider base of the red lights need to be permanently removed and 2 holes drilled into the remaining base to take the mounting plate.

The foam should be scooped out with a flat head screwdriver (which is what I started doing).

Pictures they sent show some details.  The first pic says the conduit ends there at the left rearward hole, but that's not what I saw - the conduit goes past there toward the front.  I guess when I remove the foam from the forward holes I'll see where the conduit actually ends.

Wiring diagram