The dashboard has a boolean constant that must be changed to cause the image to come from the cRIO port 2.
In addition, there may be other changes needed in the robot code specific to your programming language.
For LabVIEW, you must change another boolean constant in the begin.vi to change the source of the camera images. You must also call WPI_CameraSend Images To PC Loop.vi. See the following thread in the NI forums
https://decibel.ni.com/content/thread/11629?tstart=0 (note that the thread is still unresolved, so there may be additional changes needed).
Why do you want the camera connected to the cRIO port 2?