None. The darkness will cause the bulb to change by itself.
or
"Pint please, and one for the road."
or
Five. One to change the bulb and eleven to say they could do it faster.
or
Because she would have to move into a smaller house.
or
Five: one to handle the bulb and four to contemplate how David Sanborn would've done it.
or
Two. One to change the bulb, and one to write a song about how good the old light bulb was.
or