Actually easy to do. Drain the coolant.
Follow the lower radiator hose to the back of the engine block. There should be 2 10mm bolts holding the housing that holds the thermostat.
Remove the lower radiator hose.
Remove those bolts, some coolant may rush out so I'd advise putting some rags under there and under the car.
Pull the thermostat out, put new one in and make sure spring pin is up (also I think the word "up" is on the thermostat). The spring (from memory) should be facing away from you.
Reinstall the housing and torque down the 2 10mm bolts only to about 7-10ft/lbs! Good thing to buy a torque wrench.
Attach lower radiator hose, refill with fresh coolant.