More than once I have been disassembling a wheel to clean and repack the bearings, and totally bent up the dust cap so that it no longer fits as it's supposed to. How can I avoid doing this? They're so flexible and fragile. I use a large, slotted screwdriver and pry in different locations as carefully as possible but sometimes they still get bent. I like to remove the caps because it allows me to clean the hub much better.