Ducati ST4s Owner's Manual page 174

Undo one of the two lower screws (2, fig. 56) securing
one fairing to the other.
Keep the washer (5, fig. 56) and the wellnut (6, fig. 56) of
the plate (4, fig. 56). Keep the plate connected to a lower
fairing.
Undo the two screws (3, fig. 56) securing the lower
fairings to the air scoop.
Remove the breather hose (7, fig. 56) from the left lower
fairing.
Remove both lower fairings.
3
2
7
5
3
3
2
6 4
7
fig. 56
65
E