Have an accentra-2 FS, opened up the side panel to get to the feeder chamber, removed the wing nut, directions says slide the cover off, well...........used moderate pressure won't slide. The working area is very tight, the cover looks too big to easily remove. Anyone else run into this. Am I missing something? Oh, I'm trying to clean out fines from the feeder mechanism, manual says it should be done once a year and never did do it last year. Any help, suggestions would be appreciated, thanks