I modified one of those simple G clamp kits by making up spacers to do the removal and refitting. I found that heat was also a necessary thing to aid the removal of the old swivel joints. I'm lucky in the fact that my day job is repairing vintage motorcycles so have a lathe and oxyacetylene to heat the sockets in the axle. It was the first new set the car had and contrary to all the horror stories I'd been told it wasn't anywhere near as bad as I thought. Oh, another essential tip for using the G clamp tool is always use plenty of oil on the threads.
I'm near Shrewsbury if you're close enough I'd be happy to lend you the kit I made up.