The installation of the factory pro detent arm and spring is mostly straight forward. You will need:
Maintenance manual
Basic sockets & Hex bits
Torque Wrench
Breaker bar
Clutch basket removal tool
Clutch cover gasket
Liquid Gasket
Moly grease
Thread Locking compound
Oil
I bought a Tusk brand clutch tool for like $18 from rocky mountain and ground the ends a bit thiner to better fit the Ninja's clutch basket.
Drain your oil. Remove your clutch cover, taking care not to remove the clutch release rod or you will need to replace the needle bearing assembly that is in the cover.
Remove your old gasket and clean mating surfaces.
Remove your clutch, keeping all plates and spacers in order.
Once the clutch is removed, you can tackle the detent arm and spring. The spring pressure on the detent arm is what makes this a little tricky.
My recommendation is to spread apart the "shift mechanism arms" over the end of the shift drum before tackling the detent arm. This will give you more room to swap out the part. Do not unscrew the star on the end of the drum.
As @
GregS pointed out, once you have the new bearing in place with thread locker, do not tighten it down fully. Leave enough room to push the bearing up and in place on top of the shift star before torquing it down.
Move the "shift mechanism arms" back in place and test the shifting. If everything feels good, reinstall your clutch, gasket, cover etc, as per the maintenance manual, and add your oil.
Any additional feedback or tips are welcome.