Ducati ST4S Owner's Manual page 68

The height of the light beam can be corrected using the
screw (1, fig. 74) on the left side of the headlamp.
Remove the left side guard of the instrument panel to
expose the screw. Turn the screw anticlockwise to lower
the beam, clockwise to raise it.
E
The side position of the headlamp is adjusted using the
adjusting screw (2, fig. 75) on the right side of headlamp.
Remove the right side guard of the instrument panel (see
page 49) to expose the screw. Turn the screw
anticlockwise to move the beam to the right, clockwise
to move it to the left.
68
UP
1
DOWN
min-1
x1000
RIGHT
2
LEFT
fig. 74
fig. 75