Two: One to change it, and the other one to change it back again.
Just one but he wants to do it thirty-two times and when he's done everyone says that his last light bulb was much better.
One. We are efficient and don't like humour.
Four - three to cut a hole in the roof and one to change the bulb.
They don't change it, they just take forever to find where to fit the batteries
Because I don't joke about jokes.
Not sure, first they have to figure out which way to spin it.
