How to remove the base (bottom) cover and power light board, which must be removed to access the battery. The images and information in this guide were taken from this computer's service manual, which can be found on the product page.
After turning off the computer, use a Torx 5 screwdriver to remove the 10 screws (#2) from the computer's base.
Using a prying tool or a fingernail, lift up the base cover (#1).
Lift up the small latch which holds down the power-light board cable (#3) down. Remove the cable by pulling out sideways.
After removing the Philips screw which holds down the power-light board (#1), remove the power light board (#2) and its cable.