I use a curved hemostat to loosen the retaining ring on my lights. The curved pointed ends of the hemostat fit the holes perfectly, leaving the handles of the hemostat in a horizontal position that allows for good torque and easy loosening of the retaining ring. You can buy hemostats at a medical supply store. A cheaper source could be an emergency department in a hospital which use disposable suture sets that contain hemostats. If you know anybody who works in an ED they may be able to get you a pair.
I am not sure who sells boots for these lights. Have you checked Deal Extreme? They do carry some light parts. I would love to find a glow in the dark rubber boot for my NDI.