Click link above to open a video: 

Detailed Steps:
1. Unlock and Open the Door:
Ensure the door is unlocked and open, with the bolt/latch retracted inside the door. 

2. Remove the Interior Cover:
Locate the screws (usually three, two on the sides and one on the bottom) on the interior cover of the lock. Use a Phillips screwdriver to remove them. Carefully pull off the cover to expose the internal components. 

3. Remove the Battery Pack:
The battery pack is typically located at the top of the lock, near the door. Slide it upwards and out of the lock. 

4. Replace the Batteries:
Remove the old AA batteries and insert new ones, paying attention to the correct orientation as indicated in the battery pack. 

5. Reinsert the Battery Pack:
Slide the battery pack back into its slot, ensuring it is properly aligned with the door. 

6. Replace the Cover:
Carefully align the cover and reattach it to the lock, securing it with the screws. 

7. Test the Lock:
After reassembly, test the lock to ensure it functions correctly. The lock should beep or light up to indicate proper battery replacement.