Switching elevator/aileron to gimbal control on RC telem

Hi everyone ,
I just ordered my first APM 2.6 (previously flying a Walkera QRX350 GPS) to build an
aerial video platform (Quad or Hex). My question is can I flip a switch on my RC transmitter, I have a few channels that I don’t use, and change the elevator/aileron stick to gimbal pitch and yaw control, I would have switched to position hold first, of course. Forgive me if this has been asked/answered somewhere in the vastness of the internet (couldn’t find anything on google).

Thanks in advance

Anyone?