Fixing a game disc is actually pretty easy, all you need is toothpaste. Just spread out regular toothpaste evenly over the disc until the shine isn't visible and leave it for two or three minutes, wash it off with cold water, and use a soft towel to clean the disc. This usually works for smudges, dirt, and scratches. It that doesn't work, you'll need to bring it to a disc repairing which is usually pretty cheap.
