IIRC, the tops of the struts aren't exposed enough to grab onto with a wrench/crow's foot, right?Quick necro-bump since I'm running into a similar issue now.
I'm currently trying to take my KW DDC dampers off my ground control camber plates and running into the same issue. Unlike the OEM top hat, the GC camber plates do not have the flats/oval that prevents the shaft from spinning. Also, I've used blue loctite per GC's recommendation since I've had the top nut come loose over time, but now that I want to service them, I'm having a bit of trouble getting it off.
I used one of these for the install: Schwaben Shock Nut Socket, 17mm, 1/2" Drive - PelicanParts.com
First I tried compressing the spring just enough to exposed some of the top shaft so I can get a strap wrench around it, but it just slips. Also tried a piece of rubber pad and clamped down on it with some channel locks, but again, same issue.
I also tried hitting it with an impact driver, but I just end up spinning the shaft after a couple of taps and just end up whipping myself with the cable lol.
Any other suggestions?