The Adafruit Motor Shield is a service which will create a number of sub services. It will create 4 Motor, 2 Servo, and 1 Arduino service. This shield uses its own library, so MRLComm.ino will need to be modified.
Fortunately, the Arduino service will have the modified MRLComm.ino pre loaded in its editor. This will need to be compiled & uploaded into the Arduino.