Do you have a dremel? It's fairly easy to make a bit like that with out of an old flathead bit. I've also heard of people having luck using the melted pen trick but I've never tried it myself. You take apart a ballpoint pen. Slightly melt the end of the tube part with a lighter. Press it onto the head of the security screw. Wait for it to harden and then unscrew. Has anyone every tried this and had it work?