Abstract: A partially cutaway circular cylindrical tool for changing the master pins in an Almont lock is presented. The tool is fixedly coupled at one end along its axis to a handle which may be a key handle. At the opposite end, the tool comprises a plug stop which prevents the tool from going too far into the Almont lock. The partially cutaway circular cylindrical surface defines a master pin slot, two wire slots, a wire slot ridge, a stationary pin slot, and a pin holding cam ridge, which includes a cam adjacent to the master pin slot all parallel to the axis. Perpendicular to the axis and disposed about halfway between the end of the plug stop inserted into the lock and the point of coupling between the handle and the balance of the tool is a perpendicular stationary pin slot which entends between the master pin slot and the stationary pin slot. In operation, the tool is inserted into the Almont lock and rotated so that the master pins, which are wafer tumblers, slide up the master pin slot.