Has anyone serviced the locks on the the side panels? I need to take the roller out of one of mine. The key turns but does not move the latch. The spring, latch and part of something that I guess moves the latch up and down with the key/roller came apart in the locksmith's hand. They had the latch a few days but were afraid to drill into the housing. Is there some sort of special set screw that holds the roller in the latch housing?