I just pulled the bottom radiator hose to drain it. Refilled with water and flush, took it for a drive then drained it again. Let it cool to the touch, refilled with water, drive, drain cool. Repeated and after it had been flushed once with flush and twice with water I filled it with two gallons of 100% antifreeze and a gallon of water(it still had a gallon of water in the block).

Took all day because it takes a long time for it to cool down each time. Can't add cold water to a hot engine.

 

Bottom radiator hose that connects to the radiator?

 

Yep. Just unhook it from the radiator side and drain the system. Theres probably a valve somewhere but for me it was faster just to pull the hose than look for it

 

Make sure the MOTOR is cool to the touch before adding cold fluid to it btw