If your engine does not have the "drain hose" led up the side of the engine from a Banjo Fitting on the bottom, it would be worth adding. It was an option on our former M25XP engine, and later versions of that engine included it as standard equipment.
This allowed us to easily drop the thin tubing from the vacuum pump (pictured in reply #4, down to the bottom and pump out all of the dirty oil.
Our new Betamarine also has this oil-removal hose fitted, standard.