Simply remove the drain plugs on the manifolds one on each or if the supply hose attaches to the bottom of the manifold simply loosen the hose clamp remove the hose and allow the water to drain out. Secondly you will need to drain the block there is a drain plug on either side could be a blue plastic one or bronze, they are a little hard to find but you will need to drain these of at least 1.5 gallons per side. If once the plug is removed water trickles out or does not come out at all it is still in there and needs to be drained out. Use a screw driver, pick or stiff wire to remove the rust build up blocking the drain hole. IT IS A TOTAL OF 3 GALLONS IN A 5.7 l. and it all must be drained out. Now leave your drive trimmed down so the drive is under water where it will stay warmer. Now mind you there is still residual water in the system which most likely will not pose a problem, for example the water hose from the transom assembly to the cooler or circulating pump. Or you may simply invest in a bilge heater designed to be flame proof and will maintain the engine room above freezing. Of course the smartest thing to do is to haul your boat before the really cold weather arrives and have a professional properly care for your boat. Hope this helps, John