I managed to sqeeze the springs together with my bare hands, and then while holding the spring together with one hand, I replaced the other parts.
Just kidding! Seriously though, If you have the vehicle up high enough (with proper support, of course), you can take a floor jack, place it under the area where the lower joint is, and give it a little lift, not much....after that, you can loosen the nut that is fastened to the upper ball joint, and slowly lower the floor jack (one of my uppers stuck in place, so watch that it doesn't stick, and then jump at you...maybe give it a little love-tap with a hammer, to motivate). After you have wrestled the new upper arm into place, raise the jack, and put the nut back on. Double check the tighness after you have lowered the car, in case it decides to seat itself a little further.
Hope this helps!
-Larry (not Arnold Schwarzenegger)