Ducati MONSTER 821 Workshop Manual page 994

Use tool (B) part no. 88765.1657 to bring the piston of the horizontal cylinder near the TDC.
Carefully lift the vertical cylinder (8) off the crankcase, keeping it vertical.
If necessary, rock the cylinder slightly using both hands or tap its base gently with a rubber mallet.
Continue to lift the vertical cylinder until you can access the gudgeon pin (9).
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