Ducati Diavel Workshop Manual page 654

Cooling system: water pump
Recover the ceramic washer - seal unit (8) placed on the internal side.
Undo and remove the screws (1) with the washer (2).
Working from the generator cover (16) internal side, use a suitable punch to press on the inner race of end bearing (5)
until it can be extracted from the cover.
Use the same technique to remove the other bearing (6).
Remove the inner spacer (7).
Check the condition of the components of the mechanical seal: there should be no signs of deformation, cracking, or
excessive wear. In the case of damage, both components must be renewed.