If you break the bulb, there is also a trick which I have used successfully. Cut a potato in half, and then, carefully, push it into the socket and the base of the now shattered light bulb. Then turn the potato as you would a bulb. This will avoid the problem of using pliers to attempt to remove the base of the bulb.
As has already been noed: SHUT DOWN THE MAIN POWER DROP FOR THE HOUSE BEFORE YOU DO ANYTHING.