how do you change antifreeze

You will need to find the radiator petcock on the bottom of the radiator, usually passenger side. Open it. Open the radiator cap (not the coolant overflow bottle cap) and run a hose into it. I usually run the engine with the hose filling and the fluid draining until most of what is coming out of the radiator is clear -- water. Then you can let the radiator drain one more time, shut the hose off, and fill with 100% antifreeze, as what you are leaving in the block should be mostly water. This is pretty close to a 50/50 mixture. I've done it this way for years and never had any problems. An easier way (due to how hard it is to find someone who takes used antifreeze anymore) is to get a garage to machine-flush it for about $80. This is what I do anymore.

Wow, what a mistake. Don't get technical information from these fools