Currently Replacing L/H Switchgear on T3

I’ve picked up one of the new lego style switches currently being offered by Gutsibits and Stein Dinse for my 1976 bog standard T3.
Had hoped it would be the simple like for like wiring which my level of experience could deal with, but of course it’s not. Now find myself staring at wiring diagram as steel doors close before eyes.
Anyone else done one of these and got the idiots guide?

I have a wiring diagram for the T3 in colour that I can email to you, that will tell you what the wires on your bike do, you need to work out what the wires in the switch do and what colours they are then I would be able to tell you what to fit where, you can do this with a test meter or a battery and bulb. Do you have a photo of the switch and wires? Chris950s2014-05-02 15:01:15

I thought they come with a pre-wired plug that connects into a socket on the headlamp shell.
All the best,
David.

The lego switches are later than 76, so wouldn’t be a direct replacement. I think they came in around 78 or 79.