Ducati Diavel Workshop Manual page 466

Fork - steering head: Steering
With the service tool no. 88713.1058 loosen the nut (12) and unscrew it from the steering shaft.
Slide the seal (8), the inner ring (A) and the ball race (B) of the upper bearing (6) off the steering shaft.
Remove the bottom yoke (15) complete with the steering shaft from the frame tube.
Remove the ball race (B) of the lower bearing (6).
The inner race (A) of the lower bearing (6) and the relative oil seal (8) will remain on the steering shaft.
Using a universal puller (see figure) remove the inner race (A) and the spacer (13) from the steering shaft, taking care
not to damage the seat.
Important
Once removed, the seals (8) and the bearings (6) must not be refitted.
Using a suitable punch, remove the outer bearing races (C) from the steering head. Proceed with extreme care to avoid
damaging the seats.