Remove the two bolts holding the oil seal carrier to the cylinder block and pull out the seal carrier. Pry or hand-press the seal out of the carrier.
Reinstall the seal carrier with a new O-ring. Torque the bolts to 25 Nm (18 ft. lb.). To install the seal, lightly oil the seal and shaft's sealing surface. Fit the seal into position, and carefully drive it into place. Use care not to distort the seal as it is installed. For best results, use a seal driver such as Volkswagen special tool no. 10-203.