What happens at the end of winter?
Simple. When it starts to thaw, most of the water will evaporate over a few days or if you still have a lot of water because of a heat wave, open up the rink at the lowest level and slowly let the water drain out. Carefully take the rink apart, dry off all the parts and put them back in the box until next year. To avoid ruining the grass, remove the liner before spring.
