How do you replace the air intake valve on a 2003 Toyota Echo?

To replace the air intake valve on a 2003 Toyota Echo, first disconnect the negative battery terminal for safety. Remove any components obstructing access to the air intake valve, such as the air intake duct and possibly the throttle body. Unscrew the old valve from its mounting, clean the area, and install the new valve by reversing the removal process. Finally, reconnect the battery and check for any leaks or issues before starting the engine.