Turn off the computer, or enter hibernation mode. Then disconnect the AC adapter and all cables from the computer. Note: If you are using a PC Card, the computer may not be able to enter hibernation mode. In such a case, turn off the computer.
Close the computer display, and turn the computer over.
Unlock the battery latch  to the unlocked position.
While holding the battery latch in the unlocked position , remove the battery .
Install a fully charged battery .
Slide the battery latch to the locked position .
Turn the computer over again. Connect the AC adapter and the cables to the computer.