There is a little more to this. first you need to drain some of the antifreeze into a clean container as you will be reusing it. The drain [******] is on the bottom of the radiator. Never **** out antifreeze form the top hose or drain the top hose as you will get air pockets in the system. While you need to remove the air box and the screws on the crossover bar you do not have to remove the bar, just move it aside a bit. When replacing the thermostat I would also change the o ring gasket, you do not have to, but why chance a leak. After installing everything back together loosen the vent screw on top of the thermostat housing and attach a piece of clear hose to it and put the other end in a bucket. Now slowly fill the overflow tank until antifreeze runs out of the clear tube and you see no air bubbles. Tighten the vent screw and top off the overflow tank. now start your snake and let it idle through a few fan cycles to expel any trapped air. I hope this helps. For anyone who needs a 170 degree thermostat we have these in stock for $49.95.