1. Turn your Compaq V4003XX laptop over.
2. Find the laptop battery release button lock for your Compaq V4003XX laptop.
3. Now that your Compaq V4003XX 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 V4003XX battery is removed, grab your replacement Compaq V4003XX battery for installation.
6. Insert the battery into the slot. Push the Compaq V4003XX battery towards the laptop and secure it in place.