place a 1/2 drive socket wrentch with a 19mm socket and lay it on the sub-frame with the but end pointing to the front of the car, make sure the wrench is pressed against the frame while you bump the starter to loosen the bolt. assuming you have the inner wheel well removed tightening the bolt after you replace the dampener is a little tricky. With the battery removed tighten a C clamp around the alternator pully with the serintine belt installed and this will make it so you can tighten the bolt. no need to tighten it to tight cause the rotation of the crank and the treads on the bolt wont alow the bolt to come off during operation.