DUDE! You need a FSM!
(Factory Service Manual).
First (before jacking up the truck) remove the nut from the end of the axle. Then jack up the truck and remove the wheel.
There are (4) 12 point bolts on the back of the steering knuckle assembly holding the bearing "cartridge" in place. The fit between the bearing and the knuckle isn't a press fit but due to corrosion, they don't come out easy. I have had good results with a slide hammer type puller. The AutoZone nearby claims to have one, they loan tools for free.
When you remove the axle, be careful not to damage the seal. If you have the truck level side to side (both sides jacked up) you will have some dif lube in the axle tube when you are done. This will look like a damaged seal and whiz lube on the ground for a couple weeks. Don't worry, it'll stop.
Try doing a search on this topic, there are more complete accounts...