1. Turn your Toshiba PSAF3U-0P900VB laptop over.
2. Find the laptop battery release button lock for your Toshiba PSAF3U-0P900VB laptop.
3. Now that your Toshiba PSAF3U-0P900VB 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 Toshiba PSAF3U-0P900VB battery is removed, grab your replacement Toshiba PSAF3U-0P900VB battery for installation.
6. Insert the battery into the slot. Push the Toshiba PSAF3U-0P900VB battery towards the laptop and secure it in place.