Look at your top radiator hose and then follow it back to the engine, your thermostat sits inside that hose. Pop that hose off and you'll see it, coolant is going to start pouring out a bit so be ready for it.

Take out the old thermostat and put in the new one with the jiggle pin on the thermostat facing upward. Put the hose back and add more coolant or just do a complete coolant flush if you like... hope this helps.