If it's your first time and you're not super handy with a wrench, it won't be easy necessarily, but it will be simple at least. The FSM is really good for this procedure, get a copy if you don't already have one. You'll need a 54mm socket for the hub nuts, and a ft/lb torque wrench to retorque them. Get a tube of Permatex Right Stuff for the outer hubs and ignore the gaskets. Get a bucket of wheel bearing grease to repack the bearings. You'll want new star washers for the hub nuts, and if the dork who owned the truck before you didn't have a 54mm socket and took the nuts off with a cold chisel, you might want new nuts too. Or at least a dremel to clean up the old ones.
Pull the wheel. Unbolt the caliper and tie it off to the frame so it doesn't stretch the brake line. Pull the outer hub, then spin off the hub nuts and the rotor and inner hub will pull free. The inside wheel bearing is located by a seal, but the outer one is located by the hub nuts so be careful you don't dump it on the floor.
Clean everything up with solvent so you can get a good look at the wheel bearings - if they aren't near their mileage interval and there's no wear marks on 'em, I'd leave them be. If you don't know how old they are or they look sketchy, go ahead and replace them on general principles.
The rotor is bolted to the inner hub assembly that contains the bearings, and if it's anything like mine have always been, those bolts are good and frozen. I don't even try to unbolt them with hand tools anymore, I take them down to the shop on the corner and give them a six-pack in trade for a minute with their impact gun.
When you're retorquing the hubs nuts, you'll slip the wheel bearing in, spin on the hub nut, and torque it to 40 pounds or so. Spin the wheel forward several revolutions, then back several revolutions. Turn the nut back a couple turns, spin the wheel again. Torque the nut again. Spin the wheel again. Back off the nut, spin the wheel again. Torque the nut again, back it off without spinning the wheel, then retorque it to a final torque of 20 pounds (I think. Check the FSM!). Slip the star washer on, spin on the second hub nut until nicely snug, and fold over a couple tabs on the star washer to lock the hubs together.
While you're in there, consider taking your outer hubs apart and giving them a good cleaning too.
. The inner seal should come with the bearing, and you don't need to bother with the paper hub gaskets if you get a tube of Permatex Right Stuff gasket maker. It's better than the paper anyway.
