Lock primary drive gear (8) in place with holding tool part no. 88713.0137, and loosen sprocket retaining nut (7).
Remove the nut (7) and the lock washer (6).
Remove the primary driving gear (8) using puller 88713.2092 and interposing a packing piece of aluminium or copper between the crankshaft and the screw of the puller.
Take care not to damage the key (9) located on the crankshaft and the inner spacer (10).