its a lot of work. The first problem is usually getting the locking bolt out. Once you get it out it usually requires a BFH to drive them out. The new bushings will most likely need to be fitted using step reamers or a hone of the proper size. I am an advocate of doing things yourself. This is a job that requires special tools and is a lot of work. If you dont have all the stuff to do it, bring it to a truck place, they do kingpins all the time.
Artificial Intelligence is no match for Natural Stupidity