In Texas, the idea of winterizing when you do not expect a freeze is kinda wasteful.
Your motor, along with the Rotax motors are considered a TLCS system. Which is a "total loss cooling system"....when you pull your motor from the water, it drains all the water from your jacket. But, there are pockets of water that will be left. These pockets may range in size from a tablespoon to a 1/4 cup.
If you lived up north and was putting it up for the winter season, I'd recommend you pour a bit of antifreeze in through the top with a funnel, at your highest point of the water jacket. There is actually a plug up there for doing a pressure test, you could do it there.
The proper procedure calls for you to remove the flush line from the expansion tank, pinch some lines and fill the motor up. Then, allow if to drain out again.
Here in Mobile Alabama, where I live, it freezes maybe 2 times a year. During these periods, I just put a light bulb in my engine compartment to keep the temps up. Doing this means you are certain you have no fuel leaks or buildup in the engine bay.
I also start my motor about once or twice a month (I'm always piddling on it).
I think the most important part of winterizing for you is lubrication and moisture barrier. Spray your engine quite liberally with a water barrier such as WD-40. Spray all your linkages and the engine surfaces. This will keep moisture from forming the droplets and rusting or seizing parts of your motor. I also use White lithium grease. The manual calls for the "fogging" spary. I remove my plugs and spray a small amount of white lithium grease in each one, then I spray a couple shots into each carb. This is what engine mechanics use to coat metal to metal contacted components from rusting and seizing........
But, now when you go to start the motor up, be prepared to see a bit of smoke until the grease burns off.................:cheers: