Use your thumbs to slide the RJ-11 board away from the sound card. This is your chance to get out some aggression, as the board will most likely be very tight and require a good deal of force to remove. Don't get carried away though - don't torque the ambient light sensor and don't put too much actual force on the card itself.
You have successfully removed the RJ-11 Board. To reassemble your laptop, simply follow the directions in reverse order.