One by one, de-solder the four wires (two wires corresponding to each LED bulb) that attach the backlight to the board.

If you don't know how to solder, check out How To Solder and Desolder Connections.

Soldering irons are extremely hot and can burn you if you touch them!

If you hold the soldering iron tip at the same spot for too long, it can strip the metal from the plastic board. You may not be able to solder wire to that point again.