Pull out the liner , and look to just above the ankle area and you will see a slit on each side. Slide the spacer shovel shape down, most of it will be between the cuff and the lower shell. Red is harder and yellow is hardest. You can also expierment , like puting the yellow on the out-side only and not the in-side , this will make you fold more to the inner edge of you ski. So play around.