Ducati 999S Owner's Manual page 44

Warning
Use a specific pin wrench to turn the preload
adjusting nut. Be careful when turning the nut to avoid
hurting your hand hitting motorcycle parts. The pin may
slip out of the nut recess while carrying out such
operation.
Warning
The shock absorber is filled with gas under
pressure and may cause severe damage if taken apart by
E
unskilled persons.
When carrying a passenger and a load, set the rear shock
absorber spring to maximum preload to improve
motorcycle handling and keep safe clearance from the
ground. You may find that rebound damping needs
readjusting.
44