You will need to solder together the LED Matrix display as it comes in kit form. You can find full instructions for this on the display's product page.
Then fit the LED Matrix display into the I2C socket o the RasPiRobot Board V2. Make sure that you get it the right way around, and if you are using the latest version of the RasPiRobot Board V2 with extended headers make sure that the header pins cannot reach up as far as the bare connections on the underside of the LED matrix module. If you think they might, then just fold a bit of electrical tape or even Scotch tape over the extended GPIO pins. Attach the flying leads of the battery box to the screw terminals maked Vin and GND on the RasPiRobot Board V2. Fit some AA batteries (rechargeable or single-use). Turn on the switch to the battery box and you will see the power light on the Raspberry Pi light up, as well as the two LEDs on the RasPiRobot Board V2.
For the battery pack - the red wire goes to VIN and the black wire goes to Ground