Ducati Panigale 959 Corse 2018 Owner's Manual page 192

Warning
The shock absorber is filled with gas under
pressure and may cause severe damage if taken apart
by unskilled persons.
The two ring nuts (3) and (4) adjust the external spring
preload.
To change spring preload, slacken the upper locking
ring nut (4). Then TIGHTEN or SLACKEN the lower
ring nut (3) to INCREASE or DECREASE spring
preload.
After setting spring preload as desired, tighten the
upper locking ring nut.
Warning
To turn the preload adjuster ring nut use a pin
wrench. Pay attention to avoid hand injuries by hitting
motorcycle parts in case the wrench tooth suddenly
slips on the ring nut groove while moving it.
4 3
Fig. 114
191