I personally will never use another spring compressor in my life. Those things scare the crap out of me.
The way I do it is to get a jack under the control arm and have either a small chain or fairly stong rope and loop it through the spring just incase it tries to jump out. Then just slowly let the jack down and the spring will just fall out (most of the time anyway
)
since you are putting in shorter springs, the installation should be fairly easy and straightforward