Ian,
I put the front wheels on ramps and jacked up the rear end 18" or so, which gave plenty of access.
I did make a leverage bar to force the front of the spring into the correct position to get the pivot bolt through. It was based on what I'd seen on TM but modified to suit my 4 seater.
By about spring no.4 I could do the whole job myself by standing on the bar and 'encouraging' the pin with gentle taps of a lump hammer. To fit the final high camber spring to the RHS I had to get someone else heavier than me to stand on the end of the lever.
There is not much space above the rear hangers in a four seater and the trickiest job by far was persuading the washers on either side to remain in place while the bolt was pushed through. The solution was highly technical - 12" of 5mm dowel with a strip of gaffer tape hanging down to hold the upper face of the washer.
I have lots more details and photos, which when I've worked out how to do it, will post on here.
Am away on holiday at present but will PM you when I've worked out how to do that!
Peter's surname is Ballard and yes it's SSL of 5 link fame.
Regards,
Doug