1. Measure the amount of new hose you'll need and buy it. Use sanitation hose throughout the entire system, including the toilet intake and tank vent. 2. Pump out and rinse out the holding tank VERY thoroughly. Adding C.P. to the rinse will remove most of the odor. Rinse out the entire system--the head, any macerators or manual pumps, and the hose VERY thoroughly--with lots and lots of clean water....C.P. helps here too. If the hoses REALLY stink, it helps to smear a healthy glob of Vicks Salve under your nose before you start....a cool day also helps. 3. Map out your plan before you remove a single hose. Now you're ready to actually begin work: Remove the highest hose connection first to minimize drips, and stick plugs (available from any hardware store) in the ends of the hose. Work on only one hose at a time...and take each section of hose all the way off the boat as soon as you get it loose (your dockmates may insist you take it all the way off the dock!) . When taking a hose off a fitting, have a pan (disposable aluminum pans are good for this) under the connection to catch the drainage. Have lots of rags handy to mop up what misses the pan. 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 or saw them off...the screwdriver blade will dimple the fitting and the saw will cut into it, and the new hose won't seal. It's much easier to pull new hose through inaccessible places if you connect it to the old hose and pull the new through as you pull the old out. Use a male-to male connector...cement both hose ends onto it. Do not use hose clamps or anything that can get hung up as you pull the hose through, and be sure to butt the ends of the hose tightly together to create the smoothest uninterrupted surface possible. After you've pulled it through, cut the new hose cleanly behind the connector. 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.