Ok...
Remove the bottom rad cover....the plastic half moon cover attached to the bottom of your car.
Look at the bottom right of the rad, there will be a plastic phillips screw, facing the rear of the car. Unscrew that and coolant will flow all over the place. There really is no way to contain it all...put a bucket under there and catch as much as you can. But expect a lot of spilling.
Now understand, this is NOT going to remove all the fluid from your car...if you want to do that, then there is a few more steps. Remove the lower right hose, and use your garden hose to spray water down into the rad overflow container. You will see the water come out of the bottom hose that you disconnected....keep the flow until the water is clear.
Now remove the airbox, and disconnect the rad hose at the thermostat housing. Then let the garden hose flow through one end of that opening that you just created...this will flow out the other end...do it until the water is clear.
Key things to remember...
Get new thermostat and gasket.
Do this when the engine is cool. You do not want to spray cool water through a hot engine block. And you don't want to end up wearing a HOT COOLANT shirt.
Try to contain as much of the coolant as possible.
Any other questions feel free to send me a PM.