I might be wrong, I might have got that idea from the wrong WP shock manual. (I've been collecting them.) I did take off the preload as much as possible, so that only a mm or two of threads are left, and the spring was turning easily - I think, I need to check just how freely it turns. So if that's the case, either it can just come apart, or maybe a couple of tiedowns will be enough, for just a mm or two.
The preload spanner, I have a few C spanners, but I'm getting one of the proper ones - the aluminium ones, they look like they're all made by Enduro Engineering. The C spanners are all too thin and too sharp - they work, they're ok, but when it's tight they're digging into the alloy a bit. I've just been holding off from ordering one until I decide whether to get the EE preload cap tool at the same time, or get a normal pin spanner, that works without the handlebars having to be taken off.
mm, I see the point about two hands to pull the spring down. At the moment, I can't even pull the spark plug caps off. My wrist/whatever is buggered. After 5 weeks or so, I can do things, but I have to be careful about what angles I apply pressure with that hand. But I can organise someone to pull the spring down, and hopefully I can insert the spanner and organise something to hook the rod with. ...It'll be much easier if the spanner is very thin.