If the scratches are not too deep you can try cleaning the disk with windex and a microfiber cloth or paper towel. But be gentle with the paper towel. Other methods work such as boiling the disk. Put it in boiling water for 30 seconds and remove appropriately and dry it off with a microfiber rag.
The only scratch removers that actually work well are professional resurfacing machines. You can try using toothpaste and rubbing outward from the inner circle, but beware of creating more scratches.
