One. But he doesn't screw it in, he just holds it and the world revolves around him.
Only 2, but I have no idea how you're gonna fit both of them inside a lightbulb.
Wanna go ride bikes?
None! We don't change light bulbs. We disrupt them.
Wanna go swimming?
One. They stick the bulb in the socket and wait for the world to revolve around them!
One. He just stands there with the lightbulb and the whole world revolves around him.
Just one. All he has to do is hold it in place while the world revolves around him.
