Are king pins difficult to repair?

Still looking at straight trucks as I see them for sale locally. Two of the trucks I recently looked at the owners both told me that they sidelined the truck because the king pins need repair. I am not familiar with front end work on big trucks so I don't know if this is like replacing a ball joint on my pickup or really serious and loose your butt expensive. Both were class 8 trucks. A freightliner and an international. Other than the king pins, both trucks were claimed to be in good...

Are king pins difficult to repair?

Are king pins difficult to repair?