use the pool pump to empty it, scrub with bleach and refill.
or lay a garden hose in it and let mother nature drain it.
careful where the water goes, a neighbor drained a pool and flooded the
basement of the home next door, it wasnt a pretty site, the neighbor
got mad and tried breaking down the pool owners door, the police were
called and before it was over several got arrested, and 20K in damage
to the basement and contents.
Insurance paid but sued the pool owner. last I heard it was still in
court, the pool owner moved to get away from the mess.
someone reportedly warned his new neighbors and that caused grief
it just went on forever....