Since the battery pack on my dremel was dead, I didn't have to worry about shock.
Materials/Tools for this step
Saw of choice
3/8" Wooden Dowel
First, take a flat head screwdriver and put it in between the red and black plastic. It takes some force to pop open the battery pack. Once it is open, there will be 2 sets of three batteries. They are in a T shaped formation. Take those sets of batteries out and do whatever you want with them.
To replace the batteries that were taken out, you will be creating a replacement called dummy batteries. The easiest way to make them is to take a wooden dowel the size of a AA battery (about 3/8") and cut them to the length of a AA battery using whatever saw you want.
I had to make 6 dummy batteries for the dremel battery pack and 4 dummy batteries for the bicycle headlight that I modified. (More on the light later in the instructable)