the first time I changed the gear cable on an X0 system I couldn’t find out how to get the cable out of the lever (no little grub screw like shimano), so I undid the enticing hex bolt underneath and the lever sort of exploded springs and ratchets everywhere. I couldn’t get it back together.
but that’s not the stupid part. I figured that I just needed to know which order the bits went together in, so I very carefully opened the left hand shifter to see which way that one was put together. boom. springs and ratchets everywhere for the second time.
I paid the LBS to fix them in the end but they never really worked properly again, expensive day in the garage