Pattern side out, roll one end of ribbon until the edge is even with the remaining ribbons edge
Follow the same instruction for the other edge of the ribbon, it should appear like below
From the underside, run your thread and needle through as many pinwheel petals as you made and be sure to alternate them before going back up through all of them for the button
When through to the top side, run thread through the button and back down to tie off the thread and your done! Easy Peasy!