Embodiments of the invention relate to techniques to remove a defective head gimbal assembly (HGA) from a head stack assembly and replace the defective HGA with a good one without allowing any good HGAs to be damaged. In one embodiment, a volatile alcohol solvent is moved by gravity from a holder included in a reworking tool provided for a reworking jig to a shearing edge of a cartridge type edge mounted in the holder. The alcohol solvent is thereby deposited on the shearing edge in a drop-like shape through surface tension. The cartridge type edge is made to slide on a surface of an actuator arm and is inserted in a gap between contacting surfaces of a mount plate and the actuator arm. This assigns the drop-like alcohol solvent a function as a lubricant. Possible vibration can therefore be prevented from being transmitted through a carriage to other HGAs.