Sure.  I'm assuming this is a 4x4, otherwise you wouldn't be asking (as a
2WD uses a pair of servicable roller bearings).  With the truck still on the
ground, pop off the center cap, remove the cotter pin, then remove the big
axle nut and washer.  Then raise the wheels (both of them, so you can
operate the steering), remove the wheel, remove the brake caliper (two 3/8"
allen-head bolts hold it on - don't let the caliper hang by the brake hose -
use a bungee cord or some wire and tie it up), then remove the rotor.  If
you have 4-wheel ABS, you'll have to disconnect the ABS wire from the
connector up on the inner fender (gray plastic connector), and un-do the
clips that hold the wire all the way down to the hub.

Next, back off the three 14mm 12-point bolts from the back side of the
steering knuckle.  Back them off about 1/4" or so.  Then smack them really
hard with a hammer (may want to turn the wheels to get a better angle on
them) until they bottom out.  If necessary, back them off some more and
repeat the process, until the bearing is loose.  What you're doing is using
them to press the hub/bearing out of the knuckle.  The 1/2-tons are
notorious for siezing in place, as they have a large tapered piece that fits
into the knuckle, and this rusts up.  Since you're replacing the bearing, do
what you need to do to get it off.

Once the bearing is loose, remove the three bolts all the way, pull the
hearing off of the axle, and replace it with the new one.  Look on the old
one, and wherever you see rust, lightly coat the new one with anti-sieze
(give a light coat on the axle splines, as well).  Everything else goes back
on the way it came off.  The three 12-point bolts torque to 125ft.lbs. - the
axle nut torques to 175ft.lbs., then if necessary, tightened further until
you can insert the cotter pin (use a new one).  The caliper slide pins
torque to 38ft.lbs.  Wheel lug nuts torque to 95ft.lbs.