I did this a few weeks ago, but with one minor adjustment.
I was going from lowering spring back to stock, so the short lowering springs came out easy.
-to get the tall stock spring in, i used my strut spring compressors that i already had, then I used 2 rachet straps (1000lb rating each) to hold the spring compressed while i removed the spring compressor.
-then pry down the lower control arm and put hte spring in.
-Using a floor jack to raise the control arm and compress the spring, i could then safely remove the rachet straps.
NOTE: i do not recomend using the rachet straps to physically do the compressing. I was only using it to hold the springs. And please ensure if you try this you use high capacity straps. (i figured each spring load rating is about 750lbs, to I tripled it to 2000lbs.)
May 2014 ROTM, June 2015 ROTM
for auto-x: '04 Liquid Grey ZX3
for street: '02 Infrared SVT