Fit the RRBv2 shield over the GPIO pins furthest from the USB ports (see the picture below).
Use male to male jumper wires to connect from the 5 pin socket of the stepper motor to the RRBv2. Note that the red wire from the stepper is not used.
Try to use the same color of jumper lead as the wires from the motor. I didn't have a pink jumper lead, so I used white instead of pink.
Next connect the other end of the jumper wires to the L and R screw terminals of the RRBv2 as shown below. The order of connections from top to bottom is: orange, white (pink), blue and yellow.
Note that the screw terminals are designed to connect well even to thin leads, so you will need to first unscrew them (counter clockwise) place the lead in the hole and then screw up the connector clockwise.
Connect the battery pack to the screw terminals of the RRBV2. If you are using a battery pack with flying leads then these can be attached into the screw terminals directly. If you have a battery pack with a 2.1mm plug on the end, then either use a screw terminal to 2.1mm socket adaptor like this and some short lengths of wire.
When attaching the battery make sure that the positive (red) lead goes to the right-most screw terminal marked Vin and the black lead goes to the screw terminal marked GND.
With the battery connected, the Raspberry Pi will start to boot, it will be supplied with power from the battery pack.