It's done through the elite account Matt.
- Add a game to your Vault when playing on MW3 on the PS3
- Play the file in the vault
- Press the square button to record the part you want, press square when finished
- Save the clip to your vault that you recorded, the part from the main clip.
- Play your recorded file you just made, you will see options to render the file or share it on facebook.
- Once you render the file it will auto go onto Youtube. Thats if you have linked up your Elite to your Youtube account through the Elite account done from your pc.
At the moment it will only let you record small clips, 1 min long I think. It's good if you got yourself a good throwing knife shout or something funny, even a good sniper shot.