Two. One to hold it in the socket and the other to drink until the room starts spinning!
WAA-TAA!
He drank so much poison it built his immuni-tea.
5mins later* Me: I need a new room.
Jose can you see.....
It needed to get it's fill o' mint.
Just one, but it takes a really long time, and the lightbulb has to want to change...
EOM
Answer: I don't know, I'm no scientist
Just one. They hold it in place while the world revolves around them.
They're writing their last will and testament.
3 Lannisters.
A full set of teeth
Paddy O'Furniture
Tree fellers Edit: Wooo gold!
One. They stick the bulb in the socket and wait for the world to revolve around them!
One she holds it in the socket and waited for the world to revolve around her.