OK, Len, here goes,
Remove the recoil spring unit. Push the retainer (at the front) back along the guide until the spring is compressed. Lock it in place with padded locking pliers on the guide rod. With the front of the rod exposed, tap the peened-over end from the side of the rod until it is even with the rest of the rod. Release the retainer slowly and let it come off. The spring can then be removed and the new one put on. Then rest the other end of the pin in a vise or on something round and solid, and put the retainer on. Then again use the pliers to hold the retainer and spring, clamp the end of the rod in a vise, and peen the end of the rod over again to keep the retainer in place. (Just resting the end of the rod will not give solid enough support for peening and you can easily bend the rod.) This should work. If there isn't enough to peen, or something goes wrong, then you buy a new unit from Ruger and start again. They are only a couple of bucks.
Make sure that you don't shorten the guide rod; its back end has to be supported by the bolt stop pin. You can assemble the gun without the rod peened but then you won't be able to remove the spring and guide as a unit and you take a chance on losing the retainer on the next disassembly.
Remember, though, that there is no such thing as a free lunch. If you increase spring tension to reduce wear on the bolt stop, you increase wear and battering at the front where the bolt impacts the barrel. Factory engineers balance recoil springs to get the best results all around.
Jim