Here are the scans of the instructions. The batteries are in the rear of the box that holds the LED for the Matrix.


You need to mess about with the Matrix box and pull it out a bit as you get to this step when changing from robot to vehicle mode.


There is a way to take the box out, but it's not in the instructions, and my MP1 & 4 are packed away somewhere, sadly I just don't have the time to mess about with them ATM. If I do, pics will come as I have to check the batteries in MP4 I guess.