ADVICE FROM OUR TEAM
1- Ensure the crank cap is completely clean before inserting the tool
2- Unscrew the two screws on the left crank to unscrew the cap
3- Lift the black safety tab
4- Repeat in the opposite direction: manually tighten the cap, reposition the tab, and then tighten the crank to the manufacturer's recommended torque (you can check how to do this in the Shimano Hollowtech bottom bracket user guide)