Providing power for 2 DC Motors, 1 Stepper and 1 Servo

I am using 2 6 V DC motors, a 12 V stepper motor (Nema-17) and a micro-servo s90g. I am using an Arduino Uno with a motor shield V2.3 on top to run the whole thing. For power, I am using a Venom 2200 50C, 11.1V power supply ( I have only the battery itself, and not the modular connections that come along with it.

My main question is, how do I wire the battery to the Uno and the Motor Shield? The closest thing I have found is the Battery Wiring Harness. (
However, I cannot wait for this to arrive, or afford to have it delivered more quickly. Another issue with that is, I cannot supply power to both the Arduino Uno and the Motor Shield unless I try to supply power to the Motor Shield through the Uno, which I'd rather not try to do.

Finally, I am borrowing this battery, and I cannot make any alterations such as cutting the insulation to get access to the wires directly. What is the best way for me to draw power out of the battery? I have tried searching for alternates to the battery wiring harness on Amazon, but no luck so far.