How to bind this three-hole and one-line cover?

Hello, when binding the cover with three holes and one thread, first you need to punch three holes at equal intervals in the appropriate position of the cover, and then cut a binding line with an appropriate length and fold the binding line in half to form a double line. Next, the double thread will pass through the front of the file and form a hole on the back. Then, the two ends of the double thread respectively pass through the holes at both ends of the front face of the file until the back face is W-shaped. Finally, turn the file upside down, let both ends of the double thread pass through the hole in the middle of the double thread, tie the knot tightly, and cut off the excess thread length. In this way, the binding of three holes and one line can be completed.