Coolant successfully changed out. Thanks for the support through this forum. Shop Vac with a custom end helped empty the Hot water Heater hose and Garden hose custom pieces (with Funnel attached) with quick couplings really helped in the fill up if the engine through the Hot Water Heater hose.
And wasn't it a bloody mess when you finished ? ? ?
I went through that when I first changed the coolant on my Yanmar 2GM20F. Disconnected hoses as I removed the coolant from the hot water heat exchanger. Every hose end seemed to be at the wrong elevation. Air everywhere in the system when finished. Kept filling the coolant reservoir for the next two outings before all the air was gone.
Swore never to do that again. Now I change ONLY the coolant that is contained in the block every two years and leave the remaining coolant in the hoses and HEX. Doing it every two years ensures that the corrosion inhibitors, seal lubricants, and other magic is replaced frequently enough to keep them up to strength. Two year old coolant coming out is indistinguishable from the new coolant going in.
Hardly have any top up until all the air is gone and not a drop of coolant is lost (on the floor, on the sink top, on the upholstery, and everywhere else imaginable).