1. Turn your Sony VGN-FS660W laptop over.
2. Find the laptop battery release button lock for your Sony VGN-FS660W laptop.
3. Now that your Sony VGN-FS660W 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-FS660W battery is removed, grab your replacement Sony VGN-FS660W battery for installation.
6. Insert the battery into the slot. Push the Sony VGN-FS660W battery towards the laptop and secure it in place.