Three. One to change it while the other two argue about how old the old one is.
A. Hell you need 250 just to lobby for the research grant.
Two: One to change it, and the other one to change it back again.
November.
Only one, but the light bulb has to want to change.
Because they cant find dates
A: Seven one to change and the other six to sing about how good the old one was.
Seven - one to actually change the bulb and six to complain that they liked the old one better.
