Flush
I flushed mine in the driveway. All I did was go and buy a flush kit from autozone ($5) and hooked the garden hose up to my heater hose going into the heater core. Turn on the hose, take off the radiator cap, start truck, turn heater on high, wait til clear water comes out of radiator hole. Simple. Also don;t forget to take off your overflow and get the old stuff out of it. It just slides up. as for coolant, i used trhe HG clear stuff from autozone. works great.