Only one, but it takes nine years.
How many dragon Ball z characters does it take to screw in a lightbulb? Only one, but it'll take at least 6 episodes!
Sorry comments are unavailable on this joke.
No IT guys change light bulbs, they just keep flicking the switch on and off again until something happens.
A Brazilian.
If you lay them right the first time, you can walk all over them for years.
It was stuffed.
A: Only one but it may take him/her more than five years to do it.