Step 1: First Step
Mark these measurements on the fabric with the help of pins, remember that the has to be fold.
Now mark the shape of the pattern.
Sew that part then cut the excedent, then sew the hem of the skirt.
Step 2: Second Step
Now with the ribbons (as you can see in the pictures) finish the belt. For the last part sew the belt on the waist of the skirt.
And you're done! :)