How do I go about replacing the thermostat on my hot water heater?

To replace the thermostat on your hot water heater, first turn off the power and water supply to the heater. Remove the access panel and insulation to access the thermostat. Disconnect the wires from the old thermostat and remove it. Install the new thermostat and reconnect the wires. Replace the insulation and access panel, then turn the power and water supply back on.