how to change out the thermostat

Here are some instructions. The vehicle should sit for at least an hour before opening the system, otherwise you may get burned. 4.6L Engines 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. To install: 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