Access Door
We owned a 94 P-42. It had a small access door.You had to remove the engine door and the aft cabin door so they were out of your way. Need (in my case) two people, one laying down using the small access door in the between the two doors you removed, the other person reaching through the engine access opening (door). You also need the correct tools. I did it once then hired the "Dealer" after that to change the packing material.Thru-Hull's can be reached by leaning over the engine (put you chest on the top of the engine for support) and extending your right arm down between the other stuff to what ever thru-hull you want.