I just finished converting my hood blackout light to 12 volts and here's what I did:

I bead blasted the assembly first, then cut the old wires from the original bulb.



After that, I crushed the old bulb and removed it from the housing.



Next, I enlarged the hole slightly, so that it would accept a 12 volt motorcycle headlamp bulb. They were just laying around......





I just dropped the bulb into the hole and soldered the base to the lens housing.



For extra brightness, I soldered the original harness wiring to both of the bottom contacts so that the hi and lo filaments burn at the same time.



With the rubber cover on the back it looks stock.



Now for some fresh O.D. and it will look as good as new!