1. Turn your HP ze4520EA laptop over.
2. Find the laptop battery release button lock for your HP ze4520EA laptop.
3. Now that your HP ze4520EA 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 ze4520EA battery is removed, grab your replacement HP ze4520EA battery for installation.
6. Insert the battery into the slot. Push the HP ze4520EA battery towards the laptop and secure it in place.