Edited 22/07/17 to add Links for Photo's in the new Forum Members Gallery.
FRONT INDICATORS :If you are changing an Indicator bulb, you might also want to consider changing the type
from the standard Amber coloured ones, to Chrome bulbs - have a look at this first :
Changing Standard Amber Indicator Bulbs for Chrome bulbsThe front and rear indicators use the same "581" or "BAU15" or "PY21W" bulb type -
12v amber with offset pins ( see Photo's ).
The front indicator bulbs are accessed from behind the mirrors.
Fold out the mirror glass towards the fuel tank as shown on the respective side ( Left mirror shown ) :

Remove the wiring plug from the bulb holder, by pushing the silver wire spring retaining clip IN towards the bulbholder.
Don't try and pull the clip outwards - it is likely to come off, get dropped,
and will invariably disappear from sight inside the fairing

With the spring retainer depressed, carefully pull the plug away from the bulbholder. ( Right mirror shown ) :

You can now rotate the bulbholder "anti-clockwise" in its housing, and then remove it to change the bulb.
I find this really fiddly as it is difficult to get a good grip on the bulbholder in such a confined space,
and it is quite tightly fitted in the housing.
An alternative is to remove the indicator unit from the bike - it is only held in by one bolt !
Remove the bolt then slide the indicator unit outwards to free the retaining lug on the end of the casing :

With the indicator unit removed it is much easier to undo the bulb holder.
Twist the bulbholder slightly in the direction shown and then pull it out from the housing :



Note the offset pins of the bulb and how they locate in the offset slots in the bulbholder :

Replace with a good bulb, and re-assemble the indicator in the reverse order.
Refit the electrical connector plug which should 'click' into place.
REAR INDICATORS :Remove the rear seat. If a heated seat is fitted there is no need to disconnect -
just turn it round and lay it carefully on the riders seat.
Note the small silver wire spring clip attached to the single rear light unit retaining bolt.
This is a safety device to prevent the nylon nut from unscrewing due to vibration,
which could then result in the light unit falling off the back of the bike ! :

The spring safety clip is quite small and needs to be removed, and then the nylon nut unscrewed.
There's a good chance of dropping the spring clip and losing it, so I have modified mine by tying a small length of cord to it.
( Or you could wire it to a part of the Frame ).
This also makes it easier to remove - simply pull the clip straight out and place it to one side :


Undo and remove the nylon nut while supporting the back of the light with your free hand to make sure it doesn't fall from the bike when the nut is removed, which could damage the attached wiring.
Pull the light unit gently away from the bike to free it from its mounting, and locate the wiring plug.
Note the plastic retaining tab at the furthest end of the plug ( arrowed ).
Depress the tab to release the latch and while depressed carefully separate the connector. :

Lay the unit face down on soft cloth to protect it from scratches.
The casing is marked to show which way the bulbholders should be turned to lock them.
The next photographs show the bulbholders locked - rotate in the direction of the arrows to unlock them :


Unlocked :

With thanks to member CoJaW :
Rear indicator failure threadExamine the wiring and ensure there is no undue stress when the bulbholders are refitted,
particularly where the wires enter the bulbholder.
There has been at least one report where the wires were so tight,
that they broke under stress causing the indicator to fail.
If your wiring appears "tight" it may be possible to pull a little slack and feed through
the small tie-wraps to reduce the stress, but if not - consult your Triumph dealer !
Once the bulbholders are removed you will see that they are the same fitting as the front indicators.
Replace with a good bulb, then refit the light unit, connect the electrical plug,
refit the nylon nut, and the spring safety retaining clip.
Refit the rear seat then check all indicators for correct operation

