Thanks I ordered some cord of ebay and using the diagram managed to work it out.
Took me an hour to fit.
I guess its all in the technique. I originally tied one end to spring, went all way round, but trying to tie other end to spring again was near impossible.
So made the cord equal length and put through the spring then tied ends like a shoelace but into knots and cut of excess. All done and tuning works fine now.
Picture shows this
Which I turned into this
