Lego Nxt working with no batteries

Step 2 Inside Case

Now its times to take off the two dark gray ends. The battery pack and the main board is attached by two points of solder but only on one side. In order to pull the pieces off you must pry open the board and battery pack at the opposite end they are attached. The two gray ends are held there by two small plastic pegs. If the gap is big enough you can slide them right out. Remember the little black button in the battery case. If you separate the board from the battery pack this will most likely fall out. This is fine it is really no big deal. Just make sure not to lose it. To put it back in later I just used needle nosed pliers.

Next take two wires cut them decently long and have the diode ready. If you can see from the picture I wedged a battery in between the board and battery pack to give me room to solder.
The bottom of the usb port has 4 major solder points. The two closest to the larger side is the power.
In the picture the wire with the knot is the + (do not put a knot in the wire but a black mark because you will be routing these two wires into a small hole).

After you solder the two points run the wires into one of the screw holes(same screw holes that hold the face plate to the battery pack) to the side of the board that has the screen on it .