1986 Volvo DL 240 wagon; To take the struts off an 80's Volvo you need a specialty tool that lets you turn a lock bolt while holding stable the top of the strut rod, so it's a tool that goes over the bolt allowing you to place a crescent wrench on the rod sticking up through the box end wrench. where can I find one of these please?

 

Simply use a 1/2inch air impact, or electric impact wrench.

 

I've never used a special tool - most struts I've seen either have a flat side that can be grabbed by a spanner or use a hex bit. worst case is you can use vise grips to grab the rod (assuming your going to replace the strut anyways - who cares if you score the rod ). And yes, an impact wrench is the way to go, particulary if you are using death stick spring compressors.