Use a Phillips screwdriver to remove the three screws securing the front shell:

Two 5.9 mm‑long screws hidden in recesses on the left and right sides (one near the battery recess and one with a cutout in the main board)

You may need a flashlight to see the screws, as well as a skinny, long‑shank screwdriver to reach the one with a cutout in the main board.

One 5.4 mm‑long screw on the top edge of the main board