The greatest damage that can happen to a hot tub spa is caused from false winterization. If you are not absolutely certain that you can close your bath, seek a professional to do it instead.
Switch off the circuit breaker of the electricity or unplug the unit in whole. Remove all covers and drain the spa. You can either pump the water out or use a hose. When you are finished, leave the bottom drain spout open.
Find the spa heater and turn it off. Restore the cover and turn the circuit breaker on. Turn on the air blower for at least thirty seconds.
Remove the cover again and use a towel to remove the water from the inside of the tub. Make sure you do a good job and pay attention to places where the water adds up like the footwell. Put a large towel on the footwell to remove any water that night keep coming up.
Reach for the spa equipment pack. Press the TEST button, to trip the ground fault circuit interrupter (GFCI).
Switch off the circuit breaker found in the home breaker box and be sure to unplug the spa if it is 110 volt unit.
Find any fittings of the equipment that can be unscrewed and try to unscrew them. They are usually located in the sides of the heater or the pump and are easily disconnected.
You will soon see water coming out, which is what you want. Leave the fittings loose and remove all drain plugs you see.
Find the jet piping and drain the water that is there by any method described above. You should probably need to get in the spa to reach every jet. Keep the jets open and the topside air controls closed.
When you are done, restore the hard cover of the spa and protect it from the wind.