How do you replace the thermostat in a 2004 Chevy Colorado?

To replace the thermostat in a 2004 Chevy Colorado, start by ensuring the engine is cool, then disconnect the negative battery terminal. Drain the coolant from the radiator and remove the upper radiator hose connected to the thermostat housing. Unbolt the thermostat housing to access the thermostat, remove the old thermostat, and replace it with a new one, ensuring the gasket is in place. Reassemble everything by reversing the steps, refill the coolant, and reconnect the battery.