I do not know if my method is correct, but this is what I did. Working from the ground-up. First I built the enlarging bench as level and stable as possible, then made a platform on top of the enlarger baseboard that held a 16x20 inch easel. That baseboard platform for the easel was leveled by three adjustable leveling legs. I can elaborate if requested. It is pretty cool.

From there I adjusted the lens platform, next the negative stage. The light source by the illumination.

Maybe others can correct my procedure.