First of all, do at your own risk
Make sure the ring and stones are well cleaned with no finger proints of oils from your hands. Place in a ceramic or silicon baking dish. Place in oven, and then turn the oven on, I like 400F, some people like 350 or 375. Leave in the oven baking for 2 hours. A little more or less is fine. Once done, turn off oven and let cool completely inside the oven. Then you are done, and you can decide if it needs some more.
If so, repeat.