I wouldnt recommend doing this by your own, the scratches are too deep. And you have to remove the bezel for this task. Take it to your local watchmaker and have it fixed within minutes and without ruining your Crystal. I have polished lots of Crystals, and experienced, that replica crystals are often made of soft, cheap plexi which is burnded and melted in seconds, whereas gen. 50 years old Rolex crystals are very good and easy to polish.