Follow the procedure in Before working inside your computer.
Save and close all open files and exit all open applications.
Shut down your computer. For Windows operating system, click Start > Power button Power > Shut down.
NOTE: If you are using a different operating system, see the documentation of your operating system for shut-down instructions.
Disconnect your computer and all attached devices from their electrical outlets.
Disconnect all attached network devices and peripherals, such as keyboard, mouse, and monitor from your computer.
CAUTION: To disconnect a network cable, first unplug the cable from your computer and then unplug the cable from the network device.
Remove any media card and optical disc from your computer, if applicable.
Removing the side cover:
Loosen the two captive screws that secure the side cover to the chassis.
Slide the side cover towards the back of the computer.
Lift the side cover from the chassis.
Removing the coin-cell battery:
Push the coin-cell battery-release lever on the coin-cell battery socket to release the coin-cell battery out of the socket.
Remove the coin-cell battery.
Installing the coin-cell battery:
Insert the coin-cell battery into the socket with the positive side (+) label facing up and snap the battery in the socket.
Installing the side cover:
Align the tabs on the side cover with the slots on the chassis.
Slide the side cover towards the front of the computer.
Tighten the two captive screws to secure the side cover to the chassis.
Follow the procedure in After working inside your computer.
After working inside your computer
NOTE :Leaving stray or loose screws inside your computer may severely damage your computer.
Replace all screws and ensure that no stray screws remain inside your computer.
Connect any external devices, peripherals, or cables you removed before working on your computer.
Replace any media cards, discs, or any other parts that you removed before working on your computer.
Connect your computer and all attached devices to their electrical outlets.
Turn on your computer.
