Chris King hubs are great, they're bombproof, but they are also loud, and they need to be serviced regularly in order to keep them going well. It is actually a pretty easy job, but it takes some patience because their design is a little more complicated than some other products out on the market. I recently cleaned mine out, here are the directions for you, with pictures.
The first thing that you need to do is remove the axle and take the wheel off the bike, then remove the cassette from the freehub body.
The hub will have a collar on the side opposite the freehub body. This collar comes off with an allen wrench.
Once the allen head screw is removed, the collar unscrews from the hub.
With the collar completely unscrewed and off, you can remove the inner axle sleeve.
With the inner axle sleeve removed the freehub can be removed.
This particular freehub body is the steel body, which is much more durable. If you have the aluminum body you may want to spend the extra money to get a steel freehub, it makes a huge difference.
From here you can see inside the hub body, including the bearings.
Now, you will need to clean out the bearings, and there is probably a more complicated method but I just did the quick part, remove the split ring with a knife blade.
With the split ring off, you can remove the rubber gasket and clean out (and lube) the bearings.
There is a specific lube that Chris King sells, I'm sure that you can use some other types, but I figured this was the right stuff to use:
Before putting all of the pieces back together, make sure you clean them out well and lube them.
Because the amount of crap that just builds up in there is amazing:
Now, once you have cleaned and lubed everything, just follow the steps backwards to reassemble.