In addition to the previously posted steps and methods,  I highly suggest
that the relationship between the parts (springplate, torsionbar, and axle
tube) be marked with a skinny grease pencil or white model paint/ white
fingernail polish prior to removing the pieces. This may not guarantee that
the original relationship is preserved but will certainly be better than
starting from scratch when resetting the torsion on reassembly. 
It's funny the things you learn AFTER you step on yourself during a resto...
-ellis\
(ow, that hurts!)

BTW: Serious note~ I also underscore the saftey aspect of this procedure!!!
Keep all appendages/digits clear of the spring plate!!!