Thank you for writing. The best thing to do if follow your manufacturers procedure that is in most owners manuals. If that isn’t an option then I would disconnect the water pipes and put a wet vac on each pipe on the heat pump and suck out any remaining water. Then squirt some recreational vehicle anti-freeze in the pipes as insurance. Then I would cover the heat pump with a tarp to keep the snow and leaves out. Don’t complete cover the heat pumps sides as then you make a small solar rodent vacation home for the winter. A better option is to buy a custom cut winter swimming pool heat pump cover from me that will be hand made for your model. they don’t get any better than that.