There is the way to brake a large stone: wrap a wool cloths around your body(liver area) and place over hot ware bottle. After some time sit on the floor crosslegged or on your knees. Imagine your liver is red hot. Make nice and long exhale and freeze your chest. Now engage your abdomen into breezing. Try to make it nice and quiet. Stay there for 10-15 minutes. "Low" breezing provides gentle massage for your liver and helps to warm it up faster, therefor melting and softening stones.
Regular jogging and sauna also help to brake large stones