See a video tutorial for Step 13 and/or follow the instructions below:
On the window frames, install hinges and insulation using the M5X10 screws. Place the polycarbonate panel on the window frame and align it properly. It should lie on the screw heads on the hinges and leave a 1-inch allowance on the other end. Using a drill, make holes and use the M5X35 screws to fix the polycarbonate.
Remember that the grey-coated side of the polycarbonate should face the inside of the greenhouse. The seal is inserted in between the polycarbonate and metal frame before tightening the screws. Finally, the handle is attached in place with the M5X14 screws.