Ecklers speedometer module - help needed

[Matt B]

Hi all,

I just received my speedometer calibrator modules from Ecklers. Upon my request they told me that of course it'll come with an installation guide. Of course it didn't. Only a manual how to calculate and set the correction value was included.
Now I need some precise help on what to do with this thing. Those of you who have it installed: where exactly in your Z did you place it and to which wires does it hook up? And where exactly did you pinch the original wiring?
I'm not a dummy using wrenches and soldering iron but a C4 rookie so... Pictures would be ideal...

Thanks!

Matt