You'll first need to connect your DirecTV account to Alexa, which you can control with (for instance) an Echo, a mobile app or the new Fire TV Cube. It's then a matter of using your voice to play, rewind and record shows, or change the channel. You can search for what you want to watch too, such as movies starring a certain actor. It's a far cry from the old days of voice control, before remotes existed, when you would just ask a child to get up and switch the channel on the TV itself.