Unscrew bolts "1" and remove the camshaft sprocket from the bushing. Loosen bolt "1" of the bushing using the support key "T10051". Then unscrew the bolt by about 2 turns.
Install the puller "T10052" on the bushing and screw in the bolts "1". Remove the bushing from the camshaft, to do this hold the puller by the hexagon (SW 30) and screw in the bolt "2". Remove the bushing from the camshaft cone.
Place the inner part of the 3240 oil seal puller flush with the outer part and secure with a knurled bolt. Lubricate the threaded head of the oil seal puller, install and, pressing on the puller, screw it into the oil seal as deeply as possible. Loosen the knurled bolt and rotate the inner part of the puller relative to the camshaft until the oil seal is removed. Clamp the oil seal puller by the flat edges in a vice. Remove the oil seal with pliers. Clean the working and sealing surfaces. Do not additionally lubricate the working edge of the oil seal.
Remove any remaining oil from the camshaft journal with a clean cloth. Seal the groove on the camshaft cone with adhesive tape. Carefully place the cuff on the camshaft. Press the cuff in with the stop of the cuff installation mandrel "10.203" and tighten the M12x65 bolt until it stops.
Install the bushing on the camshaft. Tighten bolt "1" using the support key "T10051".
Install the camshaft sprocket on the bushing. The toothed sector "arrow" sprocket-camshaft should be facing up. Screw in bolts "1" not all the way. Fix the camshaft bushing with lock "3359". Install the toothed belt (adjust valve timing): toothed belt drive with hydraulically damped tension roller, toothed belt drive with friction-damped tension roller. Tightening torque: Sleeve to camshaft: 100 Nm.