Is the cable broken off in there.
It's unusual to need to replace the gear that drives the cable--or the gear in the brake plate center.
They always round out the center of drive tab that engages in the hub when the big gear seizes from lack of grease.
Also the ears on that drive plate get flattened due to miss-aligning the slots when refitting the wheel after a tyre [tire] change etc.
Sorry if i'm getting sidetracked from the original question.
I have an original Yamaha tool to unscrew that part.