I think most people on here just drain the water out, but on the Epic's there is a drain valve behind the exhaust manifold that is particularly hard to get to and can be prone to leaking.
I keep my Epic in a heated garage, but if I did have to winterize I would consider running the engine off a hose to heat the engine up ( open thermostat, etc. ), then switch to a tub of 50/50 biodegradable antifreeze until green ( or pink ) comes out the exhaust. Then I would crack the the drain valve open on the exhaust mainfold and bottom oil filter cooler hose to verify that the antifreeze made it into the engine. The antifreeze techinque seems to be a popular winterizing option for other inboard boats so should be safe for ours too.