Main battery removal and installation - ThinkPad R40/e
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 might not be able to enter hibernation mode. If this happens, turn off the computer.
Close the computer display, and turn the computer over.
Slide the battery latch to unlock it (1); then remove the battery (2). NOTE: The first position of the battery latch is for releasing the lock of the battery.
Align the side of a fully charged spare battery with the side of the battery space in the computer (1); then gently push the battery into the space (2).
Slide the battery latch to lock it.
Turn the computer over again. Connect the ac adapter and the cables to the computer.