The video is decent, but a couple of things worth adding
1) Use a vise, if you can. Set the jaws an inch or so apart and hammer the kingpin out that way. Don't hammer on concrete, if you don't have to.
2) Use making tape to mask off the area around the hole for much easier clean-up.
3) Make sure you set the nut initially with the kingpin in, so that it's oriented the correct direction when you reassemble the truck. Leaving the kingpin in so far, with threads sticking out, seems like a bad idea, but maybe it works for some people. I leave it in a few MM and just run a tap through it when I'm done.
4) Shaving the bushing is completely unnecessary. The geometry is not affected by the orientation of the kingpin. I suppose you'll get additional clearance, but with the inverted kingpin, you're already going to be well below the axle, so must of us will have replaced our trucks before we're going to getting hung up (unless you just have crazy dip with your Smiths)