Well...as Pete said,...
First pump out and rinse out the holding tank VERY thoroughly. Rinse out the entire system--the head, any macerators or manual pumps, and the hose VERY thoroughly...with lots and lots of clean water. Map out your plan before you remove a single hose...Remove the highest hose connections first, and stick plugs in the ends of the hose...work on only one hose at a time...and take each section of hose off the boat as soon as you get it loose. When taking a hose off a fitting, have a pan (disposable aluminum pans are good for this) under the connection to catch the drainage. Removing hoses becomes much easier if you'll heat them with a blow dryer to soften them up before trying to work them off. Unless you want to also replace all the fittings, do not pry them off with a screwdriver...you'll dimple the fitting and the new hose won't seal. If the job is a really smelly one, it helps to smear a healthy glob of Vicks Salve under your nose before you start....a cool day also helps. Use sanitation hose throughout--including the toilet intake and the tank vent.To put the new hose onto fittings, heat the hose with a blow dryer to soften it--but be careful! You only want to soften it a bit, you don't want to melt it. Smear a little dish soap on the inside of the hose and the outside of the fitting to lubricate the connection. Don't use vaseline or any grease...and don't use any cement or sealant...only teflon tape on the fittings. Double clamp all the hose connections. And as long as you have the entire system apart, now would be an excellent time to either rebuild or replace your toilet. If it's more than 5 years old, and if you can replace it with the identical model for about the same price as two rebuild kits, I wouldn't bother to rebuild...I'd definitely replace.
