1. Put "Scripts/Flex Skin" folder in <Ai install folder>/Presets/Scripts.
2. Put "Templates/FlexSkins" folder in <Ai install folder>/Cool Extras/Templates.
3. Launch Ai CS3.

You will see two menus in File -> Scripts -> Flex Skin -> "Create Flex Skin..." and "Export Flex Skin..." .

4. Select File -> Scripts -> Flex Skin -> "Create Flex Skin..."
5. Choose various options in the dialog and click OK
6. If required, do some modification to the symbols in the document.
7. Save the Ai file
8. Select File -> Scripts -> Flex Skin -> Export Flex Skin... and specify a file name to export the symbols to.

The swf with symbols will be saved with the specified file name.

In Flex Builder, you can use the Import > Skin Artwork menu item to import the swf you exported from Illustrator.

