Remove the 3 screws circled in red, which holds the black cap onto the actuator assembly.

The design of the black cap may vary slightly depend on the robot joint. Here J5 is pictured.

The screws circled in purple do not need to be removed.

The screws circled in green do not need to be removed.

Once the screws are removed, the black cap can be lifted up slightly, as illustrated by the red arrow. There is no need to remove the black cap.