1. Turn your Compaq R3212EA laptop over.
2. Find the laptop battery release button lock for your Compaq R3212EA laptop.
3. Now that your Compaq R3212EA 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 R3212EA battery is removed, grab your replacement Compaq R3212EA battery for installation.
6. Insert the battery into the slot. Push the Compaq R3212EA battery towards the laptop and secure it in place.