1987 300TD Turbo - Best method of draining coolant

[Chewable]

I want to remove the "green" coolant that the last owner of my car used.

Usually I have dropped the lower radiator hose and drained the system when I replace the coolant in my other cars. I have also drained it this way and then run a bunch of water into the system and drained that to ensure it flushed the old.

Is there a better method?
Can I use tap water to flush or should I use a few jugs of distilled?

[sixto]

There's a radiator drain port under the [US] passenger headlight that should be as effective at evacuating as and less messy than pulling the lower hose. There's a block drain on the passenger side of the engine. It's like a giant brake bleed nipple that'll take a 1/2" garden hose. It should be okay to do preliminary flushes with tap water. There's a coolant overflow bottle in the passenger fender behind the wheel. Follow the hose from the reservoir that tucks in the the fender by the air cleaner. I don't know if the system can draw from the overflow bottle, but just in case, remove the wheel well liner and empty the bottle so no green coolant gets back in. No need to fill that bottle.

Pull the radiator while the system is empty to clean the core. Clean the condenser core as well. Be gentle because bent cooling fins are worse than a dirty core.

Sixto
87 300D