Here is some pretty pictures to help:
Name:  2011-04-26_144549_graphic.jpg
Views: 10227
Size:  38.9 KB

Name:  2008-05-21_175216_07AleroAC.gif
Views: 11360
Size:  21.8 KB

1) How do you know you have too much freon? Did you put it there yourself?
2) What was the real problem? Your description is a bit confusing.

As our favorite Canadian frog said too much is too much and less is more in this case. Here is an article on AC in cars to help you get to speed.
HowStuffWorks "How Automotive Air Conditioning Works"

The AC in the Aveo is really simple and not much to go wrong.