Shut down the computer completely
Unplug the power cable
Remove the laptop battery if it is removable
Press and hold the power button for 10 to 15 seconds
Open the computer case or laptop back panel
Locate the CMOS battery on the motherboard
Note the battery orientation
Gently release the retaining clip or holder
Lift the CMOS battery out carefully
Avoid using metal tools if possible
Do not force the battery out
If needed, disconnect any nearby cables blocking access
Replace the battery only with the same type
Reassemble the computer after removal