Back in the day, I removed a lot of king pins on pickups and larger farm grain trucks. Some were easy, some were a #!#!#. If I had the room I'd use a drift pin that was slightly smaller than the king pin I was trying to remove. Usually an old drift pin that I had already removed from something else. Drill a hole in 2x4 to hold it, and then hit the drift pin with a sledge hammer. Of course it took another brave soul to hold that 2x4 and drift pin. Another difficulty is finding an alignment shop that will do the camber/caster on a straight axle.
