First flip the mouse over and unscrew the single screw at the bottom.

I will not be showing how to remove the light because I do not have the correct tool to do so.

A mouse works by having the red light reflect back and then it detects how much light was shown or blocked off to figure out which way the mouse has moved.

A mouse will sometimes use potentiometers, or rodary encoders to then covert the motion of the wheel spinning, to digital codes. That info will then transfer up through the mouse, through the USB cable, then into the computer. The USB cable also provides the power for the mouse by transferring energy from the computer.