You simply place the product where you want it...trace out the outline of the inner holes and cut away all of the existing stock board that would show through the windows cut 1/8 larger then the new product covers. You grind down any rivets or nibbles that keep them from laying flat and poke holes then fill with rivets. SIMPLE It then rests on what is left and is riveted in place. They add substantial strength to almost every model we sell. Certainly fair greater traction and in most cases they help in evacuating snow so that you don't slip off when you are showing off to your friends and loose your sled to a tree.