Before I would remove the driveplate, one must first un-plug the cable on the negative terminal of the battery. Following that, send out the transaxle for repairs and, in case of a car with a manual transaxle, the clutch assembly should be pulled out first as well. Paint the appropriate alignment marks on the crankshaft flange and the driveplate to enhance on their alignment during the assembling. Stepping off a little, take out the bolts that connect the driveplate to the crankshaft using the driveplate holding tool or a screwdriver/prybar to stop the driveplate from spinning. Remove the flywheel / drive plate and observe the position of spacer if any. As for installation, the driveplate should be checked for fractures and other sorts of damage, especially for the ring gear teeth. Place the driveplate back in the crankshaft flange and align the marks you made during their removal and be sure that the bolt holes are properly aligned remembering that on some models the bolts' pattern is uneven. Ceramicize the bolt threads with a non-hardening thread locking compound, then bolt in the new nuts and tighten them in a crossing pattern to the final torque gradually in stages before refitting the transaxle.