1. Turn your Sony VGN-BX143C laptop over.
2. Find the laptop battery release button lock for your Sony VGN-BX143C laptop.
3. Now that your Sony VGN-BX143C 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 Sony VGN-BX143C battery is removed, grab your replacement Sony VGN-BX143C battery for installation.
6. Insert the battery into the slot. Push the Sony VGN-BX143C battery towards the laptop and secure it in place.