When you unbolt the king pins, if the studs come out make sure you keep them in the same order as I think a couple are different sizes. I think they're dowel studs for keeping everything in the right spot.
Once you've removed the king pins you should have some shims there. You can get new shim packs. Once everything is out the way you can get a drift and tap the bearing cups out. Some heat around the area may help but I don't think it was needed for mine. Knock them out by gently going around the cup, don't try banging it out just in one spot.
Give the whole lot a good clean up. I got that polished look by using long strips of fine emery cloth. Like balling up a boot. :-D
You can now put the new cups in. Sit them in place and gently work around the ring until they're fully seated. Once they're home you should get a nice ring when you tap it with a hammer. You could put them in the freezer for a while first to help them slip in. If your axle is on the jeep then this won't help you doing the bottom ones.
You're ready to pack the bearings and put it all back together now. You may or may not need the new king pin. Mine were fine.
All my spares come from Tony Sudds.
When you put it all back together, the shims mentioned earlier come into play. You put an even amount of shims top and bottom, and bolt it up tight. Now you'll need a fishing scale or something similar. Hook it on the steering arm and pull. You should have a resistance of 4-6lbs (I need to check this is right) before it moves.
If You don't have the correct resistance then add/remove shims as required. I've heard you can do it by having all the shims at the top until you get the right amount, then just split them evenly between top and bottom. Or as near even as you can.
By the way this is done without the seals on the back of the knuckle. Once you put those on it will seem very hard to turn by hand but that's how it should be.
Hope that makes sense.