Changing the factory shocks on these trucks is hell on earth. The nuts seize onto the shocks you have to work some magic or just sawzall them off. It's a monstrous pain in the ass, especially getting a sawzall between the shock, frame, and fuel tank on the driver side!
Being in Ontario made it way worse but I've heard from many guys that it's rough anywhere. I'd imagine changing shocks you've already replaced shouldn't be a big deal. I LOADED up the nut and top of the shock with grease to prevent that nasty salt and gunk getting in there. So hopefully in 100,000km, it shouldnt be a big deal!