Gary, I'm not so much concerned with the radiator - it is pretty new. Mostly I want the technique for flushing the rest of the system.
The manual I have is for an older model, and it says to remove the thermostat, and run the engine with water and the heater full on. Drain the system using the block plug and radiator drain, then refill and repeat until the water runs clear. I just want to run water thru the system with the engine off, and I'm sure there is a way to do it, but I don't know what that is.
I'm hoping someone has an easy trick.