Under the second picture you'll see the words Schnittmuster (=pattern) and in the same line "hier herunterladen" = download here. Follow the steps and pictures, they are self explanatory. One thing I did not expect is step two: front and back are each lined separately and the stitched together with a narrow zigzag stitch.
I cut one out today which I'll sew tomorrow doing that my way, first stitch the side seams, then add the lining to the front.