Ok I'm not getting anywhere fast with this project on my 2002 330. I'm 6 hours in and have lost at least 10 lbs sweating it out and a pint of blood. I've got a generator and diesel tank that I can basically lay on top of, but I definitely can't "get in" the bilge. I can reach about halfway under the transom door from my vantage point laying on the genny.
My plastic deck fittings are brittle and I can (and did) knock them right out. However, the barbed ends may as well be welded into the hose.
Starboard side inner: I was able to break off under the deck, and the hose was long enough to reach out of the starboardmost splashwell hatch. Even there with good access, I couldn't pry the plastic remnants out of the hose without absolutely destoying the hose. Ended up cutting 1.5" off the hose and had JUST enough leeway to get it back into place. I temporarily replaced the inner fitting without changing the hose.
Starboard side outer: I can snap this off from the deck (I haven't yet) and in theory I can just barely reach it from the bilge. However, I can't see how I'll get the plastic out of the hose from where I have access. This one also doesn't look like it has enough slack to push it back into place if I need to cut. So I am holding off on that for now. The only practical thing I can think of here is cutting an access hatch into the "transom wing" that the dive door slams into. Then maybe I can reach down to get to the actual thru hull connections.
Port side: I gave up trying to salvage anything. I punched the fittings through the deck, but couldn't make any headway on removing what was left in the 6" access I had in front of the batteries. By the time I fought with it for two hours, I just removed the batteries and laid in there where I can just reach the thru-hulls. I was able to cut the old hoses off of the metal thru-hulls. The hoses on that side were in pretty poor condition although I think still watertight.
By tonight I should have three of the four replaced, the port side will be done "right" at least with new hose. But the starboard side is halfway at best. Help appreciated!