Cut off the ends of the lamp, remove the 110v 2 pin connector and add anderson power poles. YOu can also opt for cigerette plug if that meets your needs.

Here is a good tutorial on how to install power poles.

http://www.arrl.org/files/file/Public Service/TrainingModules/Technical/Anderson powerpole.pdf

If you need visual help, try this video. Note you can solder or crimp the connectors.

Tear apart your medium base bulb you use to mount the 12v bulb in. Here is my harbor frieght flouresent bulb that died a while back.

Here I tore the builb apart and was able to access the bulb internals. I cut the top base to fit the LED auto bulb I had.

Test fit the bulb on the base.

Solder the wires from the base to the bulb. Pay attention the center connection goes to the +12v side of the LED.

Plug the lamp into a 12v source and test with the new bulb.

This bulb lights up my ham radio gear very nicely. It can be powered from my shack 12v supply or via the solar panels that most of my radios are powered from.