Tahoe, where did you insert your siphon hose?

 

Right where you take the radiator cap off and pour in your coolant.

More detail:
I am happy to report that, doing that (when cold, not when system is hot or otherwise under pressure, no scalding, be safe) I can exchange about a gallon, maybe slightly less, and not get a drop on the ground if I am careful.

My dash is now quiet and does not make anymore "water sloshing in the toilet" or "walking in a swimming pool" sounds.

I can also empty the overflow in the same way; it was pretty dirty. I have realized I'll probably never get it as clean as comes out of new "Dont pay for the water, get a gallon of distilled water for a buck or 88 cents then get concentrated Prestone and make two gallons for about 10 or 11 bucks" but I did make it clean, it's a lot better than it was, looked like Campbell's Chunky Dumpling or Chicken Noodle Soup the first time and now looks pretty good. No need to do again, really, unless maybe before "winter" comes.

It was in either where the cap goes or the overflow tank in this pic. Yes, I use that siphon for both. The air comes out pretty quickly, that slow pour with the cap off after you start it up does a lot.