There really is no cure for kidney stones, you just have to let them pass. There are some things that you can do to ease the pain though:

This is from this website by the way, you can get more info here as well.

Basil has a strengthening effect on the kidneys.In case of kidney stones, one teaspoon each of basil juice and honey should be taken daily for six months. It has been found that stones can be expelled from the urinary tract by this treatment.

Celery is a valuable food for those who are prone to getting stones in the kidneys or gall-bladder. Its regular intake prevents future stone formation.

Apples are useful in kidney stones. In countries where the natural unsweetened cider is a common beverage, cases of stones or calculus are practically absent. The ripe fresh fruit is, however, more valuable.

Grapes have an exceptional diuretic value on account of their high contents of water and potassium salt. The value of this fruit in kidney troubles is enhanced by its low albumin and sodium chloride content. It is an excellent cure for kidney stones.