Special Tool - Outside Circlip Pliers: 57001-144
The 5th gear [A] on the output shaft has three steel balls assembled into it for the positive neutral finder mechanism.
Remove the 5th gear as follows.

Set the output shaft in a vertical position holding the 3rd gear [B].
Spin the 5th gear quickly [C] and pull it off upward.
Transmission Assy Installation
Transmission Shaft AssemblySystem Components
1. KIBS ECU
With input from the front and rear wheel sensors and front
caliper hydraulic pressure, the KIBS ECU analyzes various
conditions on the motorcycle, and with additional information
from the FI ECU (engine speed, throttle position, gear
position, and clutch actuation) precisely control ...
Exploded View
AL: Tighten the two clamp bolts alternately two times to ensure even
tightening torque.
G: Apply grease.
R: Replacement Parts
G: Apply grease.
L: Apply a non-permanent locking agent.
R: Replacement Parts
Specifications
...
DFI System
1. ECU
2. Battery
3. Vehicle-down Sensor
4. Exhaust Butterfly Valve Actuator
5. Vacuum Chamber (Other than US, CA and CAL Models)
6. Air Intake Valve Actuator (Other than US, CA and CAL Models)
7. Air Intake Valve (Other than US, CA and CAL Models)
8. Air Flow
9. Air Intake Solenoid Valve ...