That's a very good article, except..
I let the weight of the truck help push the old kingpins out.
One of mine took a 15 ton press to get out, the other took 12. Both sounded like someone shot a shotgun in the shop when they turned loose.
For what it's worth, rebuilding the king pins and replacing all the spring bushings, wheel bearings, etc made a huge difference in my truck. Well worth the effort...