Surprisingly little information using "search function" on this topic.

Anyway, I just got my W210 wagon back from the body shop after the Wife's little collision? The radiator was cracked and replaced and despite my specific request, they used the green stuff to refill the cooling system. My current mix is probably 50%water, 25% Merc brand fluid and 25% green stuff fluid.

How can I flush out the green coolant and replace with the Merc brand yellowish color coolant?

Was planning on pulling lower radiator hose for most of the system but I am clueless regarding engine block and heater core drains.

Outline of process and helpful tips would be very much appreciated.

Aloha