How many drain plugs need to be removed on the PCM 5.7L Apex marine engine for winterization?

Two on the block (port and starboard)

Two on the exhaust manifolds

One on the low elbow of the water pump (some don't have a plug here, so you have to remove the hose elbow between the water pump and the thermostat housing).

One on the transmission oil cooler unit

And at least one on the V-drive unit if it's a V-drive.