The sway bar is actually easiest to work on when the car is sitting, and same for the spring removal since the springs will already be compressed somewhat.
To remove the springs you'll first need to remove the shocks. To do this, remove the export brace and unbolt the top of the shock from shock tower cap. Then remove the three nuts holding the shock tower cap to the top of the shock tower. The bottom of the shock is bolted to the spring perch on the upper control arm. There are two nuts accessed from underneath. Use an extension on a socket wrench to remove these. The shocks can be pulled out through the top of the shock tower. Don't worry about anything shooting up through the top of the shock tower.
To remove the springs, you'll need to rent/loan a spring compressor from your local auto parts store. Loaner tools are generally free at stores that offer them. Generally two types of spring compressors are offered,...a Macpherson strut compressor and a spring compressor. You'll need to get the actual spring compressor. You'll need to use one like this that is lowered down through the top of the shock tower inside the springs. Then using a socket with an extension, you crank the nut on the top of the compressor to compress the springs. Once the springs are compressed you can simply lift them out. Handle them like they are a bomb. They are under immense tension and if they were to pop loose it could be a very bad situation. Set them on the ground and carefully loosen up the spring compressor.
Installation is opposite of removal...compress new set of springs and carefully set them in place. Be sure to get a new insulator to sit on top of the springs where they touch up in at the top of the shock tower.