Alright...If you've ever opened up an older lens or even used a lens with a manual aperture ring, you'll notice how it "clicks" into place at full stops. This is the mechanism that makes it clicky. Its can also be a major pain in the rear to remove and reinstall if you are not careful. Once you have the ring unthreaded a few turns, you'll be able to see the bearing. You wont be able to remove it yet because there isn't enough clearance. What will happen though is it will get bound up and stop all motion trying to remove the ring. You will have to use a pair of precision tweezers or a plastic shim (old gift card) to keep the ball breaking pressed into the hole with the spring that it normally sits in. Be extra careful not to lose the ball bearing, it is spring loaded! If you lose it, try to find it with a magnet...but if its lost forever and you don't have a substitute its not the end of the world. Just means your aperture ring wont be clicky anymore.