I recently replaced my front wheel bearing (hub assembly and all) part cost $185.00 and took me (not a mechanic at all!) About 3 hours.
All I did was: -remove the wheel
-remove the brake pads
-remove the caliper (two bolts)
-remove a mounting bracket (two bolts)
-remove the hub (three bolts)
*the old bearing took some pounding to get out once the bolts were out, which were the biggest pain. I reccommend heating the bolts because there is lock-tight substance on the threads which made them very difficult to remove.
-clean the space where the old wheel bearing/hub come from
-inserting the new wheel bearing/hub
-put back together.
I am not sure if its the same on your 04' and since you have a 4x4 it may be different. If not, its not too painful to do.