If you have a main drain and can close the skimmer valve you can either vacuum to waste or backwash, if you have a valve that does not have a waste setting. If you don't have a main drain you can purchase, borrow, or rent a submersible pump to lower past skimmer. Make sure main pool pump is off. You can get a good small submersible pump, at or below $100, at many hardware stores or Northern Tools. Have I mentioned lately, how much I love my submersible pumps? :lol:
Or if there is an area that you can drain to, that is lower than your pool, you can run one or more hoses to the lower area, use running water to get water into the hose, while holding both under water, then let drain hose down into water and it will syphon off. Be sure to keep pool side hose higher than draining side of hose. It's good also, to weight the pool side hose a bit so it doesn't flip out of pool or go up to surface and draw in air. That will stop the syphoning and you'll have to re-prim.
Way back, before I had submersible pumps, and needed to drain a "swamp" pool, that was the way I drained my pool when I didn't want the stuff going to the pump and filter, or through the drain, The more hoses the better, if your drain area can handle that amount of water. Mine all goes down hill to the woods.
gg=alice