Twitch does not support the saving of VoDs, so I am doubtful you will find assistance here. You will most likely need to reverse engineer their protocol yourself or hire someone to do it for you if you want raw files.
If you just want to share VoDs, you can use embed codes to embed them instead. Check out the embed documentation on GitHub:
https://github.com/justintv/Twitch-API/blob/master/embedding.md
https://github.com/justintv/Twitch-API/blob/master/player.md