The 3rd brakelight is held on by 3-4 bolts. Remove one of them, go buy a matching thread size bolt that is a half-inch longer. You can then either insert a 1/2" spacer around each bolt between the spare tire bracket and 3rd brake light, or stack 1/2" of washers around each bolt. Hardware stores (small hardware stores are better for this kind of part than Home Depot, Lowes, etc.) carry tubular spacers that will be appropriate. Cut to length. Raising the 3rd brake light 1/2" compensates completely for a 1" taller tire. Or just raise it 1" in case you plan to go to 32" tire later.