A method for disassembling a developing device. The developing device includes a frame configured to store a developer, a developer bearing member, a regulation member configured to regulate the developer borne by the developer bearing member, and a fixing member configured to fix the regulation member to the frame. The fixing member has a holding portion configured to hold the regulation member. The developing device includes a cover portion attached to the regulation member and configured to cover at least a part of the holding portion. The disassembling method includes cover removing for removing at least a part of the cover portion to reduce the size of a region of the holding portion covered by the cover portion.