That's not as easy as it sounds. First, if I remember correctly, you'll need to change the front spindles, brake rotors, and calipers. But I think Dave/Fuzzface2 did that so I'll tag him.
Second, you'll have to change the rear axle, or at least the axle shafts, as well as the brakes.
I think the easiest thing to do is to buy another truck, swap the parts, and then sell the parts truck.