Turn the device over and remove the two 0.5mm screws near the front of the mouse by using a Phillips #0 screwdriver.

The black screws used in the Logitech M125 frame are all the same size and do not need special consideration for keeping them separated. Silver colored screws are used on the circuit board and have broader heads.

Once the screws are removed, open the mouse from the front as it pivots at the rear.