Help needed! Altura Pannier rail removal and replacement.

[Gez73]

Evening all needing some help as per the title. Bought the new rail but am struggling to remove the broken one from the back of the pannier. The screws are facing out from the rail on the back of the bag but just turn without actually coming away from the rail or the pannier itself. On the inside there seems to be a cover over the internal side of the screws maybe covering a nut? Not managed to remove the cover to see just in case I damage something. The rails are easily bought (and it seems broken too) so I'm assuming they are relatively easy to replace, for other people! Still using the rail just having to slide the hook on after placing the pannier on the rack so as not to need to use the broken section of rail.
Thanks for any advice/help.
Gez
Sorted now! There are nuts under the cover! Tricky to access but done, hopefully for good.