1. Turn your Compaq CQ57-210 laptop over.
2. Find the laptop battery release button lock for your Compaq CQ57-210 laptop.
3. Now that your Compaq CQ57-210 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 Compaq CQ57-210 battery is removed, grab your replacement Compaq CQ57-210 battery for installation.
6. Insert the battery into the slot. Push the Compaq CQ57-210 battery towards the laptop and secure it in place.