haha, I've done it 4 times without a spring compressor... I wouldn't install regular springs again without one (kinda dangerous) but if you know what you are doing then its easy to uncompress them by un attatching them from the pillowball and putting a floor jack under the rotor/strut/etc. and letting it down slowly... easy.
I'm not just crazy, its very safe, though trying to put springs on some struts is kinda hard unless you weigh atleast 200 lbs.
as for installing the teins, you dont need a compressor, just lower them all the way and install... easy
just so you know, I've had 3 different sets of springs under my car, and installed springs on PDHaudio83's car, and AODfan's car... they can attest its not that hard.