5" buffalo box cover

[Ed from chicago]

Hi all, I have a main shut off in my parkway, that has a pentagon nut (cover) on it. I have loosened the nut but the cover is not moving. Can any tell me how to get the cover off.

Thanks

 

[hj]

They put the pentagon nut on it because they DON'T WANT you to remove it, but the bolt locks into a toggle that holds the cover in place.