Find out what your side bevel angle is. I think the Dakine has a 90 degree angle, and 88. Use the less rough side of the file. Slap the green part on the base. Follow the arrows. Long even passes a couple of times. Repeat on the other side, and you're good to go for like another 5-6 or to 10 days of riding. It basically tunes or sharpens the side, and gives you that sharp edge corner that it makes with the base.