Ok I've done this a couple times if your careful it works. Take the flashlight style bulb and break the glass. grab the center wire with a pair of pliers and pull on it while melting the solder with a iron on the bottom till it comes out. (kinda a 3 hand deal) then use a single LED slide the pos down thru the middle re-solder it and solder the neg to the top edge of the base. Test it then fill in the base with silcone and let it harden. It's not that hard to do and it works great if your mainly going for visabily not for lighting the road up. Remember the LED's have to have the polarity right to light up. They are all 3v I think so 2 batteries work perfect. (I bought a bag of ten off ebay for 3-4 dollars)