you cant fix it.. thats not entirely true.... lol its really hard to diagnose the actual problem with the xbox because it could be number of things that are triggering it to not work properly. Best way is to just send it to Microsoft if its still under warranty.
if the console is still under warranty, which wouldn't be hard to accomplish seeing as they have a 3-year warranty for the red rings, 1 year for everything else tho. Go to their website and fill out the form to send it back.
you have to send your device back to microsoft and they will fix it for you. As far as i know there is really nothing you can do to fix it on your own.