1. Turn your Samsung X520 laptop over.
2. Find the laptop battery release button lock for your Samsung X520 laptop.
3. Now that your Samsung X520 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 Samsung X520 battery is removed, grab your replacement Samsung X520 battery for installation.
6. Insert the battery into the slot. Push the Samsung X520 battery towards the laptop and secure it in place.