Four. One to change the bulb and three to make a t-shirt about it.
One. They stick the bulb in the socket and wait for the world to revolve around them!
One to hold the bulb, and the rest to screw the whole world.
All of them.
One. Vegans have the same capability of changing a lightbulb as non-vegans.
I am not sure, I haven't seen them try and I can't do it either.
Two, but don't ask me how they got in there.
A Casual Tee.
A dog has a better understanding of no.