I was doing this in my project page so thought seeing as it's a common-ish problem i'd put it up here .
I took the seat back off, soz, no pics of that but it's dead easy.
push the 3 round plugs on the plastic trim covers out from behind and the trims pop off.
push the circlips off and waggle the seat back about til it comes off.
once you have the seat back off the fiddley part begins.
==============================================================================
this is how the wire is supposed to locate in the hook that should lift when you pull the lever up.
this is where one is missing from
these four spikes need bending upward to allow the fabric to be pulled up
leaving something to gouge your hands and arms on. nice.
once you've lifted the cover over the spikes you should be able to pull the cover 2/3rds of the way up the seat and see whats broken.
in my case this, the diagonal cable to the inside hook.
it should go across the seat back , through the loop , through a slot to the hole (arrowed) in picture 2 above
PART TWO
=================
got the cable from GSF - £4.41 . part no. 191-881-596a. remember thats for the longer inner cable.
this is how it should fit on the outside of the seat
then across the back to the inside
once its fitted and working it's time to put it all back together.
pull the seat cover down then pull the bottom up first making sure you put the metal loops (ringed in red) over the corresponding spikes.
it should now look like this
then pull the top over and bend the spikes back in.
and thats it. now just to refit into the car.