Here's how I winterized my SV233 with the H5 engine. I owe a big thanks to Stoked for already providing a lot of this information in a previous post.
Steps I took:
1. Changed oil and filter using this: https://www.amazon.com/Jabsco-17850-1012-Premium-Marine-Changer/dp/B001CX0WX4
You will want to warm up your engine for several minutes to get the oil warm enough to flow. This oil changer works by putting the clear plastic tube down the oil dipstick tube. Takes probably about 10 minutes to empty with warm oil. Place a ziplock bag (pretty sure I used the gallon size) over the filter when removing the filter to catch all of the oil and not have it drip into your boat.
2. Pull all your blue drain plugs. There are 9 on the H5. All of them are pretty easy to see/find with the exception of the V drive. That one is hidden. Here are some photos: There are 3 on the port side; 5 on the starboard side; and 1 on the V drive. I screwed all of the blue plugs into the holder that's attached to one of the engine dividers to make sure I got them all.
3. Pull your heater lines where they are connected to the engine and either blow out with an air compressor using a blow gun (don't get carried away with too much air; the heater cores are just tubes) or use a shop vac to blow them out (thanks H2O King!).
4. Now put all of the blue plugs back into where you pulled them out of. Be gentle with these putting them back in. It's easy to cross thread them and screw them up. Go easy and you won't have any issues.
5. Add 5-6 gallons of antifreeze to the engine. I ended up adding a T kit to my raw water intake to make this easy. Here's what I used: More to follow in the next post.