Measure and mark the vertical center of your wall panel. Follow the same procedure to mark the 47-inch peg rack for screw placement. Pre-drill 1/8-inch holes in the shelf according to your marks. Again, if you have fewer than three studs to attach your rack, add a bead of adhesive around the back of the shelf. With the help of your assistant, center the rack horizontally at the vertical center of your panel and screw into place with dry wall screws.