[Tapiozona]

I remember reading about people's earcups falling off their Denon D2000 and D5000's and mine finally did. I still have all the pieces and it's really easy to fix but the problem I'm having is finding the right tool for the job. The little nut which holes the earcup onto the band countersinks into the metal and I can't get anything around the nut to tighten it enough since it's in a little hole.

Can anyone point me in the right direction. Couldn't seem to find any threads or walkthroughs on the topic.
Thanks