PURPOSE: To avoid a damage to a protector main body and clips, and to reuse them, by inserting a specific demounting tool to a clearance generated between the protector main body and a door, and releasing the engagement of locking claws.

CONSTITUTION: Both holding pieces 25 and 25 of a demounting tool 22 are inserted to a clearance generated between a protector main body 15 and a side door 10, and the engagement of clips 17 is released when a door protector 12 is removed. In this case, the clearance 21 is generated between the protector main body 15 and the side door 10, while a small external force is applied to the protector main body 15 so as to project the tips of both locking claws 17c and 17c from a locking hole 14 to the outer side, and under such a condition, both locking claws 17c and 17c are grasped by the pair of holding pieces 25 and 25, so as to release the engagement to the locking hole 14. Since the demounting is carried out in such a way, a damage of the protector main body 15 and the clips 17... can be avoided, and all members can be reused after the repainting of the side door 10 and the like are finished.