Husqvarna TC 450 Workshop Manual page 365

Remove the upper fastening screw of the the headlamp carrier to the instrument
panuel support; push forward the headlamp carrier and pull it towards the high
in order to uncouple from the two lower supports. Remove the headlamp carrier.
Remove the plug on the cable located behind the headlamp carrier.
Assemble the "dual mode" button connector on the above mentioned cable.
Assemble the "dual mode" button next to the L.H. commutator and fasten it with
the supplied clamp.
Part. N. 8000 H1344 (10-2009)
"KIT" ASSEMBLING INSTRUCTIONS
O.35