You realize that this is in the "how-to videos" section - right?
I don't have a video, but here is what I do to prepare for winter in Rhode Island with my O'day 35:
[EDIT] I forgot to mention that I live in a townhouse-style condo in MA without a basement, so I don't have room to store all this stuff.
I start the whole process by removing and flaking the sails. I remove the battens and store them below. I put the sails in their bags, and stow them in the cabin. I open every compartment (drawers, bilge, under settee) to allow air to flow throughout the cabin and the bilge. I put a solar vent in place both of my dorade cowls so that air is forced through the cabin. I stack the cabin cushions on top of the bagged sails, and try to ensure that air can flow around them as well. I also clean and polish the windows in my dodger. Once the windows look good, I remove the dodger canvas completely and store it somewhere "out of the way" in the cabin. [/EDIT]
First, I turn my attention to my Universal M25 engine;
- I FILL the diesel tank and add some extra biocide.
- I run the engine to warm it up, and then I change the oil and oil filter.
- I vacuum water out everything along the raw water system, by tracing my way through the system: strainer, raw water pump (remove the impeller and set aside as a spare for next year), heat exchanger (change the zinc), waterlift muffler.
- I FILL the transmission with ATF to keep the seals moist during the off-season.
- I look at the Raycor fuel filter and consider changing it. I usually don't. If there is any dirt or moisture in the bowl I would change it. It was last changed at 436hrs, and the engine currently has ~800hrs on it. If I were to change it, I would also change the secondary at the same time.
- Liberally spray WD-40 on the engine and wipe it down as best as I can. While wiping I look at the alternator / raw water pump belt and check its condition.
Then I winterize the boat;
- Wash the deck and pay particular attention to the anchor locker and the rode. Make sure that the cockpit scuppers are clear.
- Rinse and pump out the holding tank - repeat at least three times.
- Drain the fresh water tanks
- Drain the hot water heater
- I then use a compressor to blow air through all the freshwater lines and valves. This sounds arduous, but it takes me about 5 minutes. I long-ago removed the Y selector valve (2 tanks) and added a 3 valve manifold. During the season I can select either tank or draw from both, or shut off both tanks and draw from a third source, which during winterization is either compressed air, or an antifreeze bottle. I pressurize the line to ~30PSI and open each valve until air comes out.
- Then I add about two gallons of -60ºF PROPYLENE GLYCOL antifreeze and run it through the system until I see purple antifreeze come out each valve. I add some of that two gallons to the holding tank too - just in case.
- Vacuum out any dirt or water from the bilge. Then I add about a ½ gallon of auto antifreeze concentrate in case water finds its way here.
- Charge the batteries to 100% and then disconnect everything connected to the negative leads. I connect a battery tender for the few times in the winter that I visit my boat, but this is optional.
- I loosen the coupling bolts so that IF there is any flex in the hull, it will not strain the driveline.
- I shut off the fuel line to the engine at the tank and I tape over the fuel vent with blue painter's tape.
- Then I build a frame so that the shrink wrapper can do his thing.
During this process I also verify that I exercise each through-hull, and will do so again in the spring.
I do not remove the remnants of the drive-line anodes. I leave these in place until spring when I will replace them.
I hope this helps.