Yes I did mine, firstly i went to the helpful dearship parts manager, Quote; 'Yes the bits are about £20, the workshop techs hate doing them,its a seat out and removal of the complete seat cover.
After having a good look I concur with them, however I did fix my own, Take seat out its easy, remove the various trim bit and upolstry clips and peel/tease up the seat back cover partially to expose the mechanism, at the end of the cable there was a cast alloy crank shape that engages/disengages the seat mech. This had snapped off on mine, After thorough investigation, I decided that it would be extremly difficult if not impossible to replace the entire cable without completely removing the seat back cover. Instead I fabricated a new crankshape and joined it with an electrical chocky block,then soldered it all together as well. Tricky, but worthwhile and it has lasted, I would have liked a complete new cable but this was an option worth trying for me.