Three:
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.
or
Take regular water and just boil the hell out of it.
or
I said, "I've been on telly but I'm no Dean Martin".
or
You're the only bright spot in my life.
or
Two, one to call Daddy, and one to get the (pick one:) mineral water/Tab.
or
I don't know. I didn't think sheep could knit
or
By renaming it Trump University.
or