Tutorials on Lapping?
 

I recently took out and cleaned my 12A engine but I am noticing some step wear on the center and back iron by the spark plug areas. I'm unsure of the amount for now, going to try and get the dial measurement hopefully soon. But it's a big enough step where I can feel it with my finger going over the top, nail doesn't quite catch though.

I know the tool for lapping an iron is around 180 bucks. I live in Utah and haven't found a place that can lap them within 6-10 hours of me. So I'm trying to get information about the lapping process and what resources I can gather to try and see if I can do myself as I have access to a mill and a drill press at my job, been awhile since I've used one though.

Can anyone provide me documents, videos, etc on the lapping process or possibly someone that does it in Utah or any of the surrounding states?
Thanks!