What did your doctor tell you? Sometimes you just have to increase your water intake and wait for it to pass. If you can retrieve the stone, it can be analyzed as to its composition - like calcium. My mom was plagued with kidney stones when she started taking calcium supplements in middle age. Once she stopped taking it, no more stones. Everyone is different though. Knowing what the stone is made of can help you make dietary changes to prevent new ones from forming.
If you don't have pain and discomfort, you'll probably just have to drink water and wait. In some cases stones break up on their own and pass unnoticed. If they hang around for a long time and get too large to pass, your doctor can do a procedure to help bust it up into smaller bits and pass. Surgical removal is a last resort.