Sharpie Holder Kit comes with a top Yellow plate, a bottom Yellow plate and 4 screws.
Though the plates look similar, the hole spacing and sizes are made for specific purpose and plates are not interchangeable.
Attach the plates as shown in picture above, and fasten with the screws provided.
The screws for top plate are fastened from above, where as screws for bottom plate are fastened from below.
WARNING: While using with Sharpie be mindful of where you draw, as Sharpie lines are not easily removable.