you are correct
You are correct, there is no way, at least with my car to get the spring in without a compresor. With the control arm bolted in and pushed all the way down I still needed at least an inch and half compression.
Now, contradicting what I just wrote. You could by placing a jack under the control arm, jack up the control arm, line up bolt holes, bolt in control arm etc.
Actually, that's how I got the spring out. I undid control arm, with ball joint still attached to strut and guided down with my jack, big floor jack. Of course, my jack slipped and my brother and I were almost killed when the spring per-twanged.
I can't imagine puting it together that way. Those springs are incredibly dangerous.
I was sure glad to get that job done.
It would be great if the local members of this forum could arrange a meeting, maybe a get together in Southern NH, Northern MA. Were we could talk shop in person and I could thank you guys. The help provided in this forum is invaluable.