Wow! Very nice truck. If they are lock ring wheels, it's really not that hard to change tires. I've done way too many of them myself. For me the hardest part is always removing the old stiff tire that's become one with the wheel. Tire shops use a curved face sledge hammer, and I've tried that too, with mixed results. Pretty easy to mash the wheel edge. One way is to place the tire under the truck and place a bottle jack on the sidewall of the tire as close to the bead as possible and jack it down. Another old trick I have tried is simply driving over the tire with another heavy vehicle. I've had some success with this method. Some say if you have a tractor with a loader, that it works pretty well to break the bead down. My tractor is a 51 Ford 8N and the loader just lowers with gravity so it won't work. In the end, it always boils down to determination and brute strength. At 58, I now drop them off at my local gas station and the tire guy is pretty good at it and it is usually about 45 bucks and so I'm in my shop building kitchen cabinets and they'll toss then in my better half's pickup on her way home from work. I have fought some epic battles with those 7.50 x 17s and those 8.25 x 20s but it just seemed like work at the time........ PS. Now I see what they mean by the narrow fender lip on your front fender with the bigger wheels!