For 'normal' conditions, the obvious answer is to blanket the spinn behind the main, douse the sock or furl the spinn, then drop the sock + spinn or drop the furler + spinn.
In sudden and unexpected heavy winds .... The 'safest' without a sock or spin furler ... is to unfurl the jib/genoa & tighten the jibsheet, and with the jib + Main 'blanketing' the spinn, and with either the tackline pulled tight or spinn pole full down & the spinn sheet pulled tight, and the spinn halyard 'slightly' released and so the head of the spinn and its halyard does not become tangled in the genoa top swivel ..... then TACK through the eye of the wind and heave-to (the spinn now blown 'onto' the windward side of both genoa + main).
To lower simply 'peel' (pull) the spinn down from the windward side of the jib/main and into a turtle or down a hatch, etc. while slowly releasing the spinn halyard.
To do this you should have a spinnaker crane at the mast head - lessens the chance of the spinn becoming wrapped or tangled in the spinn. top swivel .... and all the rigging (pre-verified) without any 'sharp' edges that would snag/tear the spinnaker during the 'peel' (pulling the spinn down along and from the windward side of the genoa/main). Then reef the main, etc. etc.
This is easiest to do on a fractional rig and short LP spinn, but can be done on a mast head BUT you have to verify this will work during 'light wind' conditions before you attempt it in heavy winds. This isnt a 'racing' technique, its a survival technique. You must practice and verify that this heave-to technique will work on a boat in 'benign' conditions before attempting to do it in blammo conditions. A good characteristic that when after you heave-to the boat will be 'more quiet' during the 'peel'.
I do this a lot with my 'Scows' (no socks, no furlers) when single handing and I get overwhelmed with a sym-spinn up. I also occasionally heave-to to drop my immense A-kite on my crab-crusher. The rigging/mast, etc. HAS to be 'clean' to do this AND you must carefully watch the genoa top swivel so that the spinn doesnt get wrapped up in the top swivel/genoa 'roll'.