Tools and methods are provided for scarfing rotor blade segments. A rotor blade segment includes a pressure side and a suction side. A tool includes a first guide configured for mounting on one of the pressure side or the suction side, the first guide including a first curved rail and a second curved rail spaced from the first curved rail. The tool further includes a second guide movably coupled to the first guide at a scarf angle, the second guide including a guide rail extending between and movable along the first curved rail and the second curved rail. The tool further includes a cutting device movably coupled to the second guide, the cutting device movable along the guide rail and operable to remove material from the one of the pressure side or the suction side.