special note: not so simple on most french cars, those internal allen key nut jobbies are absolute ****s to get off! you just go crazy with a grinder on these n hope for the best![]()
I usually just cover in wd40 and wind a new nut on and off the thread a couple of times to clean it up. The nut on it should then come off quite easily. If still stuck and you aren't replacing the droplink, a jack under the anti roll bar should put enough pressure on the top thread for the bolt to undo.
Never had to grind off a droplink and done it probably 50 times on 306/106/xsara/saxos even on ones that hadn't been touched in ten years.