Does the block have drain valves on it? Need to get that water out. If not heard you can use an air hose? I think.
Get the fuel out of the tanks too. If you can. Fuel out of the carb(s) too.
There is other cool tricky things smart guys on here do, but this is a good start.

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On my trailer running water connection, a garden hose with a funnel and two cans of anti freeze cooling liquid. start up the engine and pour the cooling liquid in the funnel until you see it coming out of the exhaust, and presto your engine is winterised the Dutch way