Ballast pumps will drain automatically....they are higher than the bags and in floor tank. I remove my rear bags just to be safe. I also disconnect the hose for my bow bag once I use the pumps to drain as much as possible.

2016
2 blue plugs
V-drive plug directly under the prop coupler
Heat exchanger plug behind the oil filter
Open the raw water pump cover - leave open until spring and change impeller then
Manifold crossover hose OR brass plugs - one on the bottom of each exhaust manifold close to the v-drive (my 2015 has plugs not a hose)

Heater loop is closed loop don't need to worry about it.
Fuel stabilizer and fill the tank to avoid condensation

I leave the center drain open after every trip to the lake and all winter. Allows any liquid that drains to exit the hull.

Last year it took about 35 minutes to winterize. The other 2.5hrs were fluids/filter and spark plugs.