Misty, follow [guide|4867|this guide] to get to your lens. Now you could try to disassemble the lens, however, I usually run into trouble with trying to get parts for any of those components. I would suggest to replace the lens. If you do want to clean it, I suggest to clean it with a soft brush and 90+% isopropyl alcohol, as well as some compressed air. Clean thouroughly between the individual rings and see if this will get it unstuck. Use a vacuum cleaner first to get any dirt from all those little crevices.