87 Sailfish through hull replacement

I am attempting to replace the through hulls as they appear to all be original. I am mostly concerned about those below the waterline. Am having trouble with what I believe is the deck and fishbox drain on the starboard side. I am accessing them though a wood panel in the stern of the head (giving access under the deck below the helm) then through a round access panel to the hull. Problem is the access hole is well forward of the through hull fittings and I can't get my hands in to remove the hose or the lock nut. Add to it the hydraulic pump for the trim tabs is in the way. Is there another way to access these fittings? Thanks

87 through hulls

If interested job is complete. Spoke with the factory guys and while they wanted to help, had no good advice without me providing pictures. Unfortunately the boat is 600 miles from where I live so each trip needs to produce results. I used a router/cut-out tool and elongated the access plate hole about 5" x 3" toward the stern. Then I used a wood chisel to break the connector from the outside of the hull so I did not have to mess with undoing the locking nut. Climbed back into the access area behind the head and had just enough hand room to pull the hose back to where I could get at it and effect the change. Don't believe any structural integrity was lost and with the access plate ring back in place, the new hole looks fairly inconsequential. FYI this was the drain from the starboard fish box. There is still another right next and to the stern of this through hull that is for the live well drain; pray it holds up for the season and can wait till next year.