If you have a broken spring the easiest way to get the recoil apart is actually to drill the head off that Allen head screw with a 5/16 drill. The head will fall off once you get to the shank of the screw. The remainder of the bolt unscrews easily.
Use caution since the spring jumps out at you when it unwinds.
If you heat the end of the old spring with a mapp gas or propane torch you can form a new loop with needle nose pliers. Heat and then Quench the spring end when you are done so it will hold its shape again.