From the owners manual it is counter clockwise
Street Cup, Thruxton, Thruxton R,
Bonneville T100 and Bonneville T120
Bulb Replacement
To replace the direction indicator light
bulb:
Carefully twist the lens anticlockwise
and remove from the indicator to gain
access to the bulb.
Gently press the bulb inwards and twist
anticlockwise. Replace with a new bulb.
Installation for the bulb is the reverse of
the removal procedure.
Caution
When installing the lens, make sure
that the locating tangs are correctly
aligned to the indicator body.
To install the indicator lens, align the
locating tangs with the indicator body
and twist anticlockwise to secure.