Cut top threads off then drill the rest out. Start with small drill bit then work up to nut size, then you should be able to hit the nut with a hammer and job done.
I'm aiming to keep the fasteners in a usable condition if I can, I'd rather sacrifice the strut as I have a new set to replace them with.
You will obviously need a new nut though and i think that one is a special,domed on bottom ?
Yes it is the domed one, I think because it sits on the upper strut mount bearing. Received the cutting discs this morning, so one way or another this
will be coming apart one way or another.