Soften the corn in warm water. Hold the corn plane against the corn or callous so that the edge of the blade is in contact with the hard skin. Carefully pare down the hard skin using slow light strokes to remove fine layers of dead tissue. Take care not to remove normal skin. To change blade pull metal ridge of base plate towards handle. Insert new blade and push back to secure. CAUTION DO NOT USE ON INFLAMED OR DAMAGED SKIN. NOT TO BE USED BY DIABETICS OR IN CASES OF CIRCULATORY DISORDERS. TAKE EXTREME CARE WHEN HANDLING BLADE. KEEP OUT OF REACH OF CHILDREN.