I believe it is as simple as subscribing to a live YouTube channel, See if you can find the launch of the P3, they demoed it there, seemed pretty simple but who knows for sure....I am sure there is a YouTube of a YouTube of someone demoing it.... https://support.google.com/youtube/answer/2474026?hl=en
Livestream feature will be available in the DJI Pilot app that will be released along with the Phantom 3. Just bear with us for a moment. The dev. team is working really hard to polish every details that is possible before making it available to our customers.