S197 Mustang driveshafts are two-piece. Therefore, removal requires pulling two 13mm bolts in the support brace where the two shafts meet. The reason for marking this brace is so you can return it to the factory location. You also must remove the four 12mm bolts to pull the driveshaft from the transmission output shaft balancer. You'll need another person in the car to shift the transmission in and out of gear to rotate the driveshaft so you can access the bolts. Be sure to take note of the spacer locations.