2's curriculum, Week 2, "Backpack" Step 1: Place the bag upside down with the flap facing you. Opening will be at the bottom. Step 2: Fold the bottom up so it fits just under the flap. Step 3: Staple the sides of the bag together, stapling the “insides” only. Step 4: Staple the each strap to the bottom of the backpack. Step 5: Staple the other ends of the straps to the top (flap part) by inserting the stapler inside the side edge of the flap.