I used the Rebound adjustment rod to mark the 3.9" that the Busa requires the fork fluid to be at. Measurement is taken from the top, with the upper tube fully bottomed out on lower tube. Draw a mark at appropriate level.
Hold rod inside tube, and the bottom of the rod should barely touch the end of the rod when the mark is level with the top of the tubes.
Install new spring, or old one if you like. Lower it in so you dont splash oil everywhere.
Grab the spacer and compressor, place over the fork springs, and compress once again, and slip the spacer-jam into position. Before you compress, lift the rod to the fullest extended position, it will sink slowly as your compressing, so work quick. If its too low to get the jam plate in, thread fork nut onto rod and lift the rod while compressing spring.
Before final install of fork nut, measure to ensure there is 11mm of thread showing from end of the rod to top of nut. If not your adjustment range will be hindered. Also, locktite on the fork nut. Tighen fork nut while holding jam-nut.
Compress spring again to remove the plate. Let the spacer assembly ride up and engage the fork nut.
Lift the upper fork tube up, and tighten the fork nut to the upper tube. Congrats your done! Not really, you have one more fork to do. But dont you already feel better about this!