1. Turn your Sony ESU85TN029AA laptop over.
2. Find the laptop battery release button lock for your Sony ESU85TN029AA laptop.
3. Now that your Sony ESU85TN029AA 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 ESU85TN029AA battery is removed, grab your replacement Sony ESU85TN029AA battery for installation.
6. Insert the battery into the slot. Push the Sony ESU85TN029AA battery towards the laptop and secure it in place.