An empty lighter (I used bic mini as I had a thumbdrive for this)
A large nail (brute force is needed at times)
A saw (hacksaw's good)
a dremel or sanding block etc (smoothing edges)
Step 1: Knock the ends off
After this pry off the metal part of the top and you'll see that the flint wheel is held between 2 plastic legs, push these apart to pop the wheel off and expose the flint tube, a spring and little stone like cylinder should have fallen out. Now take your nail and slide it all the way into the tube. Hit the nail with a hard blunt object, a hammer's good but not necessary. Shake out all the plastic that's now broken off.
Step 2: Insert the Usb part
I used a 2GB datatraveller
I know it's a quick and dirty case mod but it looks cool and should take 15 mins to half an hour.
Make sure your lighter is empty as there is no way I'm claiming liability for someone that dumb...