One team, but they'll label every piece of the old one, mark its location in the room, and write a detailed description before determining that it was used to store cornmeal.
One to write the light bulb removal program,
one to write the light bulb insertion program, and
one to act as a light bulb administrator to make sure nobody else tries to change the light bulb at the same time.
One. He gives it to six Californians, thereby reducing the problem to an earlier joke...
In earlier work, Wiener  has shown that one mathematician can change a light bulb.
If k mathematicians can change a light bulb, and if one more simply watches them do it, then k+1 mathematicians will have changed the light bulb.
Therefore, by induction, for all n in the positive integers, n mathematicians can change a light bulb.
 Wiener, Matthew P., <11485@ucbvax>, Re: YALBJ, 1986
Two. One to take out the bulb and drop it, and the other to try and sell it before it crashes (knowing that it's already burned out).