The switch will be hidden under a cover to prevent debris from entering the device or being displaced. This step will remove that cover.

The cover will be secured by a latch and a screw.

Use a screwdriver to remove the screw by twisting in a counter-clockwise motion.

Using a flat head screwdriver, push the latch upwards and into hole from which it protrudes until the cover loosens.

Do not forget to separate and categorize your screws for when the mouse is being put together.