Dude, did you get your bulb out yet?

A few ideas for you.

1. Get a plumbing test plug at the hardware store that will fit into a
light bulb base. They have an expandable rubber housing that is
adjusted with a nut on the top. I'm not sure if they make them that
small, however.

2. Epoxy and a fat bolt. Glue the threaded end of the bolt in the
socket and use a socket wrench on the bolt head when it's dry.

3. Get a wooden dowel the same diameter as the socket, cut it in half
lengthwise. Insert both halves into the socket and wedge open it with
a lag bolt inserted into the cut. Turn the dowel (not the bolt) Be
careful when wedging it with the bolt, you will be tightening the base
as you turn it. Also be careful you don't expand the socket out of
round.

4. Try using right angle snap ring plyers. You can find them in any
automotive store.

5. Mud over the recess hole with joint compound and light the room with
a desk lamp.