I picked Wall-e up for approx. $34.99 ( http://www.ShopSmart2.com )
I picked up an Ez-b kit for $169.00 USD ( http://ez-robot.com )
The only thing this toy had was a circuit board to make noises like Wall-e. Everything else was manual for movements, including the arms, the neck and the tracks. No other electronics.
Step 2: Voice Module - Extraction
Step 3: Installing the EZ-B module
On the bottom of the EZ-B i soldered the power wires because there is no room to put the power connector in there, if you want you can cut a hole in the side of Wall-e where the power jack ends up that way it is easy to power him up on the bench and not waist batteries when your testing.
I know on my picture it shows the battery pack direct to the board, but what i did do is put a switch inline, you will see where i mounted the switch.
Step 4: Vision Tracking Camera
I took the camera and disassembled it so that I could fit it into one of the eye sockets on Wall-e, because this is the small version of Wall-e it was tight, but it fits fine.
You will have to modify the top piece for the back eye cover as i did below, then it fits nicely over the camera.