1. Mark the 2x8 board as specified above - dowels are space 4-1/4" apart from center to center, 2-1/2" spacing from outsides.
2. Drill holes for the dowels with a bit sized for the dowels.
3. Drill smaller holes inside the larger hole for attaching screws through the back. This screw should go all the way through the back.
4. Glue dowels inside the larger holes.
5. Attach screws though back predrilled holes.
6. Attach mount brackets on both sides
7. Paint and let dry