Nope, there's no guide. Picked up 10 x 1n4002 diodes for 99p off ebay (100v 1A).
Remove the two screws that hold the switch gear together underneath the switch.
Prise open and remove from handlebar.
Remove the 4 small screws that hold the switches in the housing.
Remove the button (mode button) so you can remove the switch from the casing.
Tin the ends of the diode and make sure you solder it to the correct wires as per photo - also make sure you put the diode on the right way..
Start the bike and operate main beam to check it works ok, refit in reverse order!
I've got some led bulbs to go in there too so the load on the lighting circuit isn't a concern.
Yep I've done the exhaust servo mod, I posted that a little while back.
https://forums.overclockers.co.uk/showpost.php?p=29937587&postcount=13786
Also got a lead and GuzziDiag software to keep tabs on the Italian electric gremlins.