I just picked up a Canon 100-400L off CL for my fiancee for dirt cheap (about $400 cheaper than going used prices). The catch is that the lens was dropped on the filter, shattering the filter glass and bending the filter ring in a way that is preventing it from being unscrewed. I tested the lens extensively before buying and otherwise it is in perfect shape, flawless glass, IS works, AF is accurate, etc. I'd love to get this filter ring off, anybody ever done something like this before? I've tried rubber bands, filter wrenches, rubber gloves, etc. I've read about bending the filter ring in with pliers to reduce the diameter of the ring and remove, or also cutting into it with a dremel. Anybody tried anything like this? I think the pliers idea is manageable, but the dremel kinda scares me. Or should I just leave it alone and be happy with the lens?