After sucking up a bolt with my Kirby 510 I cracked the fan case. While a fan case is being located and shipping, I decided to take the machine apart to clean, polish and oil it. It is all apart but the armatuer doesn't seem to want to come out. Is there a special trick or screw to remove the armatuer. I don't want to take out the field coil, unless I have to. The picture below shows how far along the disassembly is. Any suggestions would be helpful.