1. Turn your HP DV8135NR laptop over.
2. Find the laptop battery release button lock for your HP DV8135NR laptop.
3. Now that your HP DV8135NR 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 HP DV8135NR battery is removed, grab your replacement HP DV8135NR battery for installation.
6. Insert the battery into the slot. Push the HP DV8135NR battery towards the laptop and secure it in place.