Have you ever done pads before on a vehicle, if so this will be a walk in the park.
How many miles on your truck, who's pads are you using? Pads are important so don't buy any cheap one, you might look at Atlantic British, they offer 3 lines of pads, buy the best you ccan afford. Don't forget to buy at least 2 pints of DOT 4 brake fluid so you can do a gravity bleed when you are done.
As for the actual brake job, remove the wheel use a wrench to remove the 2 caliper bolts, pull the caliper off and remove the old pads. Compress the piston slowly and carefully install the new pads, make sure they have lots of sound deadening material on the back of the pads, and reinstall the calipers.
When you are done, pump the brake pedal a couple of time and then start on changing the fluid. Remove the old brake fluid from the resevor, put in new fluid then start at the right rear and one the bleeder screw and allow it to drip untill you get clear fluid, close it and go on to the next doing the same untill all 4 are done and you are finished.
Good luck, Mike J.