I have a home made 5 gallon "gerry" can with a 4 foot hose on the spout. Fill it with antifreeze, shut the through hull valve and leave the top off the strainer. Start the engine and let the antifreeze run into the strainer, it will gobble five gallons in about 3 minutes or less so I have 2 or 3 extra gallons opened and ready to pour into the strainer. My able bodied assistant will be at the back of the boat with a clean glass of antifreeze and an empty glass. She will catch the exhaust water and when the color matches the undiluted antifreeze she hollers to me and I shut the engine down.
Done in less than 5 minutes!!
I use -50 degree RV antifreeze. (pink). And as a further precaution, after the exhaust water runs pink, I restart the engine and run 2 gallons of 50/50 glycol through it. At about $10.00 a gallon it's cheap insurance.
I use Rotilla straight 30 weight, but that is another thread if you want to get into it. Brian Smith says "straight 30 weight" and that's what I use.
Comodave has the right procedure and sequence for the Rancors and Secondarys except mine are higher than the fuel pick ups and will not self fill. Many people have a priming pump for this situation, I don't . I just fill them to the top with a portable fill tank with a small hose and thumb screw valve.
I have also installed hoses onto the drains at the bottoms of the Raycors. Since they are fairly high I can totally drain them through these hoses and don't spill a drop.