Ducati MONSTER S4Rs Manuel D'utilisation Et Entretien page 130

Turn indicators (fig. 54)
Loosen the screw (1) and detach the lens (2) from the turn
indicator light.
The bulb has a bayonet-type base: to remove it, push it in
and turn it counter-clockwise. Push in the new bulb and
turn it clockwise until it clicks into place. Refit the lens by
inserting the tab (A) in the corresponding slot in the turn
indicator.
Refit and tighten the screw (1).
Brake light (fig. 55)
To change the brake light bulb, loosen the two screws (1)
securing the lens (2) and remove it. The bulb has a
bayonet-type base: to remove it, push it in and turn it
counter-clockwise. Push in the new bulb and turn it
clockwise until it clicks into place. Refit the lens.
A
2
2
1
fig. 54
1
fig. 55
55
E