Ducati 620 SPORT Owner's Manual page 56

Stop light
To replace the stop and parking light bulb, unscrew the
1
two screws (1, fig. 62) that secure the glass and remove
glass. The bulb has a bayonet-type fitting: press and
rotate anti-clockwise to remove; fit the spare bulb by
pressing and turning clockwise until it clicks (fig. 63).
Refit the glass and tighten the screws (1).
E
fig. 62
fig. 63
56