Cat Dog Door Flap Extra with 4 Way Locking Security Weatherproof Pet Kit for Kitten Puppy Safety

Installation method: Tools required: electric drill, iron saw or electric saw, measuring ruler. Step1: First use a piece of paper to draw the size of the door cover (there may be an error of a few millimeters). Step2: After the drawing is ready, draw it on the door and draw the seal with a pencil. Step3: Use a drill to drill a hole in each of the four corners of the painted door, and then if you have a chainsaw, start digging out the holes directly. Step4: If it is a glass door, use a glass scratching tool to gently open it and fix it with glass glue. Step5: The hole is ready, now make a layer of wood to wrap around the hole for the sake of beauty. Step6: Install the cat door and screw it with a screwdriver if there are accessory screws. Step7: The screw port is also equipped with a screw cover, press it on, and OK, you are done!