Arduino Esplora to MIMIC connection

I want to connect an Arduino Esplora to a MIMIC via the COM1 port. When I do this, the MIMIC still remains in control of the MōVI's mechanics (pan, tilt, roll, etc...). How do I override the MIMIC's control and allow for Arduino control?

I have successfully controlled the MōVI via the Arduino when I connect directly into the GCU.