How do you you install thermostat in 1997 Infiniti QX4?

To install a thermostat in a 1997 Infiniti QX4, first, ensure the engine is cool and disconnect the negative battery cable. Drain the coolant and remove the upper radiator hose, followed by the thermostat housing bolts. Take out the old thermostat, clean the mating surfaces, place the new thermostat in position (with the spring side facing the engine), and reassemble by reversing the disassembly steps. Finally, refill the coolant and check for leaks.