I just registered to tell you that I am very happy and grateful for this detailed explanation and step-by-step in 2021.
It still works! I just moves my libraby from my old and trusty Aura H20 (V1) to the Clara BW. Even though they have different firmware-versions (both from the same date according to:
https://pgaskin.net/KoboStuff/kobofirmware.html but still different) --> Worked perfectly!