1. Turn your HP zt3331ap laptop over.
2. Find the laptop battery release button lock for your HP zt3331ap laptop.
3. Now that your HP zt3331ap 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 zt3331ap battery is removed, grab your replacement HP zt3331ap battery for installation.
6. Insert the battery into the slot. Push the HP zt3331ap battery towards the laptop and secure it in place.