Disconnect the negative battery cable and replace the pump seal/O-ring. Look for factory paint marks indicating driveplate-to-crankshaft alignment; if absent, create alignment marks using paint or a center-punch. Remove the bolts securing the driveplate to the crankshaft, using a screwdriver to jam the driveplate if the crankshaft turns. Carefully support the driveplate while removing the last bolt and clean it to eliminate grease and oil, checking for cracked or broken ring gear teeth. Lay the driveplate on a flat surface to check for warpage with a straightedge, and inspect the mating surfaces of the driveplate and crankshaft. If the crankshaft rear seal is leaking, replace it before positioning the driveplate against the crankshaft, ensuring alignment with the marks made during removal. Some engines may have an alignment dowel or staggered bolt holes for correct installation; apply Teflon sealant to the bolt threads before installation. Use a screwdriver through the starter motor opening to prevent the driveplate from turning while tightening the bolts to the specified torque, and complete the installation by reversing the removal steps.