How do you replace the alternator on a 1985 B250 Van?

To replace the alternator on a 1985 B250 Van, first disconnect the negative battery terminal to ensure safety. Remove the serpentine belt by loosening the tensioner, then unbolt the alternator from its mounting brackets. Disconnect the electrical connectors and take out the old alternator. Install the new alternator by reversing the steps: connect the electrical connectors, secure it with bolts, and reattach the serpentine belt before reconnecting the battery.