Nope, there is a lot more to it than just unpinning, there is a major block of steel in there that prevents you from folding.
Arsenal will be able to reactivate the stock, it was actually designed so that they could do that fairly easily. While it's there, have them thread the muzzle.
Then it's under warranty and you've got the original company doing the work for you.
Good luck, they are beautiful rifles!