1. Turn your HP nw8440 laptop over.
2. Find the laptop battery release button lock for your HP nw8440 laptop.
3. Now that your HP nw8440 laptop battery is unlocked, find the battery release button down.
4. Holding the laptop battery release button, gently pull your battery away from the laptop.
5. Now that your HP nw8440 battery is removed, grab your replacement HP nw8440 battery for installation.
6. Insert the battery into the slot. Push the HP nw8440 battery towards the laptop and secure it in place.