Anyway to remove the large aluminum cover on the end of the steering box end?

[D-n-Tyke]

During the build of this truck I rebuilt the steering box. Was super careful, took my time and made sure everything was super clean, and lubed up all the o-rings when installing them. None the less the box is leaking from the big aluminum cover at the end. Does anyone know of a way to get that cover off without having to dis-assemble the whole steering box again? I was hoping to just pop it off with it still installed in the truck. Any suggestions would be greatly appreciated.