Open the petc0ck on the radiator and drain it. Refill the system with DISTILLED water. It's available at any pharmacy for a dollar or two per gallon. Start it up and turn the heat on full blast. Let it run for about 10 minutes until it's up to operating temperature. Shut it down. Let it cool for a while. Repeat. Do that 3 or 4 times. That will flush the system almost 100%. Drain the radiator one last time. Refill with Zerex G-05 coolant (not the kind that's already mixed with water, but the pure coolant). You should now have approximately a 50/50 mix of G-05 and distilled water.
Total cost will be less than $10 of distilled water, a gallon of antifreeze, and a little of your time. Don't forget to properly dispose of the used antifreeze/water.
Best,
p.s. I had to write petc0ck because apparently pet**** is a naughty word in this bizarre world.
