1. Turn your HP 7400 laptop over.
2. Find the laptop battery release button lock for your HP 7400 laptop.
3. Now that your HP 7400 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 7400 battery is removed, grab your replacement HP 7400 battery for installation.
6. Insert the battery into the slot. Push the HP 7400 battery towards the laptop and secure it in place.