Is it possible to EASILY disconnect and remove the camera for practice flying?  Or perhaps turn it off so it goes limber and the plastic camera holder can be installed without interfereing with the interal computer that controls the camera?

I don't know if it's possible, I think it is (somebody more expert will help you)... but just for curiosity... why are you thinking to do that?
It's only to avoid camera damages?

If it's only for practce flying I recommend you to practice in the simulator or buy a cheaper drone fot its purpose.

I camera is not made to be removeable during flying. If your worried about crashing and damaging the camera you can buy cheap Syma drone or something like that and practice until your comfortable with the Phantom.  Something like this http://www.amazon.com/Syma-Explo ... keywords=syma+drome

Hi ,
Sorry but it's not recommend to do that . If you are going to practice your flying skill , you can buy a Phenix RC simulator or a cheaper drone .