To the studs, I attached the plywood piece I'd cut from the former support for the old TV with three 2 1/2" wood screws on either side. Then, using the template that came with the TV mount, I centered and leveled it on the plywood, taped it in place, and drilled holes for the 2 1/2"x1/4" lag screws that came with the mount. To give them sufficient purchase, I attached horizontal 2"x4" pieces to the back side of the plywood. I used the 4 lag screws, then added 4 smaller-gauge 2 1/2" wood screws with washers for good measure.