go to the blackops official website it explains how on there somewhere
Theater Mode is a built in feater in Black Ops, ready to go. you can record your games, or make 30 second clips and upload them to the internet. If you want to upload them,Go to the official Black Ops website. Then create a Call of duty account if you don't have one yet. Once that done, go to the Banner where it says "Game, Media, downloads etc." Click Theater (Beta). When you make a clip in Black Ops theater mode, it has to be no longer 30 secs for you to be bale to upload it. So when you have a clip, click "Render" in black Ops then it will automatically upload to COD.com. If link your YouTube account with your COD account, whenever you render a video it will automatically upload to your YouTube channel too.