Well... I'm finally going to tackle an upgrade that I've put off long enough... Adding a livewell pump-out & a backup bilge pump. But, I'm stumped on how to gain access to the underside of the top cap for installing the new thru-hull fittings. Would it be OK to cut some access holes inside the aft compartment to reach through? The aft-most section of the interior panels seem to be much thicker than the panels just ahead of them.

I didn't want to cut access holes before I asked the experts here... Are these panels structural in any way?

I would need to cut a big enough hole to get hands & tools in there for tightening the jamb nuts, attaching the hoses, & tightening the clamps. Access holes are needed in the panels pointed out by the red arrows...

Starboard side...


Port side...


Any constructive advice would be appreciated!!