Looks like a ton of wasted space inside. Or maybe that is space for hard drives? where are the white dots? In the middle of the buttons on the front? If the power wires to the lights are soldered to the board or go straight into the power supply then your only choice may be to cut them or to cover them up. I have used dark colored cellophane sheets layered over bright lights to dim them without totally disabling them. But if the lights are inside of buttons then that isn't a good option.