I just dug up my old hints from Heloise from last year on what to do if you need to drain your equipment during a freeze.
Contingency Planning for Power Outages and Equipment Failure during freezing temps for Texas pools:
If you lose power or have equipment failure during extreme cold weather, you need to have a contingency plan to drain the water from your equipment and exposed pipes to prevent damage.
Step 1 - Flip the breaker to the pool equipment so that it does not try to run when the power is restored.
Step 2 - Drain all of your equipment including your pump(s), filter, and heater. Each of these will have 1 or more plugs at the bottom for quickly draining the water out of the equipment. Know where these plugs are before you need to use them, and if you need any special tools (Pentair filters usually take a 7/8 size wrench).
Step 3 - Open up all valves, pump basket lids, and anything else that will allow the remaining water in your system to expand if it freezes without breaking anything.
Step 4 - Cover the equipment with a tarp to help retain heat and prevent any trapped water from freezing.
Step 5 - Protect your skimmers by adding cut-up pool noodles to absorb the force of the ice as it freezes and expands. In a pinch, empty plastic water bottles with the lid on tightly in the skimmer can accomplish the same thing.
Most importantly, make sure you know how to do all of the above well before freezing temperatures hit. You do not want to be out there at 2 A.M. with a flashlight and freezing temperatures trying to locate your drain plugs.