How do you replace alternator on 2002 Chevy Express van with a 4.3 liter?

To replace the alternator on a 2002 Chevy Express van with a 4.3-liter engine, first disconnect the negative battery cable. Remove the serpentine belt by loosening the tensioner, then unbolt the alternator from its mounting bracket. Carefully disconnect the electrical connectors and remove the alternator from the engine bay. Install the new alternator by reversing these steps, ensuring all connections are secure and the belt is properly tensioned before reconnecting the battery.