1. Turn your Acer 3820T laptop over.
2. Find the laptop battery release button lock for your Acer 3820T laptop.
3. Now that your Acer 3820T 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 Acer 3820T battery is removed, grab your replacement Acer 3820T battery for installation.
6. Insert the battery into the slot. Push the Acer 3820T battery towards the laptop and secure it in place.