I've been reading all the posts I can find about closing the pool. I plan to drain below the returns (3), blow out the 2 skimmers plus main drain and add antifreeze which I will buy at Leslies. I plan to blow out the intake lines from the pump side, insert "gizmos" at the skimmer and plug the line at the pump.

Question: Where do I blow out the return lines? The return line starts at the pump as one, go through the filter and then the heater after which it splits to 3 returns.