1. Turn your Dell 1645 laptop over.
2. Find the laptop battery release button lock for your Dell 1645 laptop.
3. Now that your Dell 1645 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 Dell 1645 battery is removed, grab your replacement Dell 1645 battery for installation.
6. Insert the battery into the slot. Push the Dell 1645 battery towards the laptop and secure it in place.