Step 3: Rewire the battery holder
Then pull the contact and wire out of the case. See second picture
Now you will insert this contact and red wire to the other end of the case to complete the circuit. Notice how I am running the red wire inside the battery chamber.
See third picture
Now you will need to run the red wire to the corners like shown to make room for the battery. A small screw driver or thin blunt object helps. Be careful not to cut the wire or break the insulation.
See 4th picture