ALWAYS either resurface the rotors or install new ones when you replace the pads. Assuming that the pads have not been on there long, you may be able to sand them down and reuse them.. If they have FM embedded in them, or are not straight and wearing even, then youl will need to replace them as well. Personally, if the rotors are OEM blanks, it is about as cheap to buy new blanks from Rock Auto than to have the existing ones cut. Plus each time you turn a rotor, you decrease the rotating mass and cooling capacity. I would recommend a good set of replacement blanks and Hawk pads, with SS caliper bushings and SS lines. You will notice a sizeable difference in stopping performance, Remember to bake in the the brakes per the pad recommendations- normally you do a few 25-5 hard stops then some 40-5 hard stops to properly set them up.