Hi Ian,
I found the bottom nut to be a real bugger. From what I have found out the works units had the bottom nut loctited on sometimes which could cause a problem. With mine I found that I had to attack the nut with a centre punch to get it off which destroyed the nut but eventually got it off. I also found that the thread had splayed a little around the screw driver slot so had to gently work the nut on the thread (it took hours) as well as using a needle file to to clean the last of the thread where someone had made a bit of a mess of it.
Also as the strut itself is also threaded I did not take the nut right off so as to protect the thread when using a screw driver on it. Due to the limited access I had to modify 2 screw drivers to fit at angles so I could unscrew it from the casing. All of this was done using lots of releasing oil which helped a lot.
At the moment I have got both nuts off but one shock still in a strut as I cannot get the thread loose to unscrew it from the strut casing, was going to take it a specialist for advise before knackering the thread but we are currently lambing so it has had to drop back a bit on the priority list.
If required I could take a photo of the modified screw drivers once lambing has calmed down a bit (week or so but that will be dependant on the sheep
).
Hope this helps (If it doesn't make sense - blame it on the sheep, lambs and lack of sleep).
Marc