Here are some instructions. The vehicle should sit for at least an hour before opening the system, otherwise you may get burned.
1. Drain the cooling system to a level below the thermostat, or all of it if you wish to change the fluid.
2. Disconnect the upper radiator hose at the thermostat housing.
3. Remove the two thermostat-housing retaining bolts and remove the thermostat housing.
4. Remove the thermostat and O-ring seal.
5. Make sure all mating surfaces are clean.
6. Install the new thermostat, new O-ring, and thermostat housing.
7. Install and alternately tighten the thermostat housing retaining bolts to 15–22 ft. lbs. (20–30 Nm). Connect the upper radiator hose.
8. Fill the cooling system