AaronN, I think Hal is just looking to remove the barrels from the action, and not the fore-end piece from the action bar. I imagine undoing the single screw will do the trick. It would be easier if his gun had Mr Lepage's innovation, seen here:
I have to say, though, the notion of having a hinge pin that can be easily drifted out and replaced would make the task of keeping the barrels on-face that much easier. That said, I haven't come across many quality pinfires that are loose.
Those are nice thick fences on your gun!