For anyone wondering about the replacement kingpin, here's my convo with the lurpiv insta account:
I dont know how to import the video but i bet if you messaged the same thing theyd sent it, basically the replacement pins should be put in as regular kingpins (not inverted).
The video is interested, it shows and narrates the kingpin getting hammered in AS IF IT WERE INVERTED, i.e. from top to bottom, and then removing it and hammering it in from bottom to top as a regular kingpin. not sure what this first step accomplishes as I haven't done the install yet myself.