honestly, when i did my rears i didnt use a spring compressor, unbolt the strut and let everything fall as far down as it can and then just use a lil bit of muscle.

actually i didnt use a spring compressor on my car at all for the fronts i just laid a huge ass log over the spring and slowly unbolted the top bolt. had a piece of plywood and foam set up right in front of it so when the nut came flyin off it wouldnt go into the neighbors windows or somewhere lost forever...