1. Turn your Gateway T-6818c laptop over.
2. Find the laptop battery release button lock for your Gateway T-6818c laptop.
3. Now that your Gateway T-6818c 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 Gateway T-6818c battery is removed, grab your replacement Gateway T-6818c battery for installation.
6. Insert the battery into the slot. Push the Gateway T-6818c battery towards the laptop and secure it in place.