The back springs in many cars are still separate from the shock absorber and it is those back springs which often fail. I have replaced them on several cars and can only conclude that the job can be done safely as long as you use a pair of reasonable-quality spring compressors - two of them, one on each side of the coil so that it can not pop out. These are used both during the unloading of the old spring as well as when installing the new ones.