Just one. But it takes five episodes.
One. But it takes the whole emergency room to remove it.
Two, but I don't know how they got in there.
One.
Only one but he has to have a nurse to tell him which end to screw in.
Find out next time, on Dragon Ball Z!
Find out in the next episode of Dragon! Ball! Z!
An episode of The Biggest Loser
How many dragon Ball z characters does it take to screw in a lightbulb? Only one, but it'll take at least 6 episodes!