Well, I'm not sure if there is already a topic about this, but I have worked out how to change the batteries in the 2006 Exo Force light bricks. Read on to find out how.
I will post a video instruction link as soon as it is uploaded to YouTube.
What you'll need:
ExoForce Light brick (obviously)
A small screwdriver ( or other item with a long, thin shaft)(my s'driver was 2mm (0.07 inches) thick)
a small 3V battery.
1. Put the point of the screwdriver into the hole in the brick (where you'd normally put the fiber optics cord).
2. Using quite some force, lever the screwdriver until the 'lid' pops up at the front.
3. Insert the screwdriver into one of the small gaps at the side where the 'lid' pops up, and lever the lid up again.
4. the lid should come right off. From here, you can shake the brick and the battery should fall out. Simply slide the new battery in and click the lid back on.
There you have it Eurobricks.
Stay tuned for the video.
EDIT: Video link here: http://www.youtube.com/watch?v=9LoQcCHRTZk