1. Turn your Toshiba P105-S921 laptop over.
2. Find the laptop battery release button lock for your Toshiba P105-S921 laptop.
3. Now that your Toshiba P105-S921 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 P105-S921 battery is removed, grab your replacement Toshiba P105-S921 battery for installation.
6. Insert the battery into the slot. Push the Toshiba P105-S921 battery towards the laptop and secure it in place.