Ducati Diavel Workshop Manual page 456

Fork - Steering head: front fork
Slip the dust seal (20) off the outer tube (24), prising it off with a screwdriver.
Remove the circlip (22).
Important
Take care not to damage the fork tube - calliper unit (19) and the seat of snap ring (22) in the outer tube (24).
To separate the outer tube (24) from the fork tube - calliper unit (19), pull sharply outwards repeatedly to gradually
displace the bottom bush (23).
Insert the tip of a screwdriver in the slit in the bush (25) and open it up sufficiently to slide the bush off the fork tube -
calliper unit.
Remove the following parts from the inner fork tube:
- bottom bush (23);
- collar (12);
- sealing ring (21);
- circlip (22);
- dust seal (20).