Question: how to change a lightbulb
Option 0: Leave the power on so you will know if new bulb works Allow The Bulb To Cool, Use A Ladder if necessary, Remove The Old Bulb, Insert The Replacement Bulb, Switch On The Power, Dispose Of Your Old Bulb.
Option 1: Turn Off The Power. Never attempt to change a light bulb with the power still connected.  Allow The Bulb To Cool, Use A Ladder if necessary, Remove The Old Bulb, Insert The Replacement Bulb, Switch On The Power, Dispose Of Your Old Bulb.
Answer: 1