Here's the wiki page about it if you want to read it in full: http://claw.wikidot.com/custom-icons
1) Create a new folder in the Flash UI directory called Themes.
2) Create a new TXT file in the Themes directory called themes.txt
3) Download an icon pack that you want to use. Extract the files of the icon pack into a folder (name it something short and easy to remember)
4) Put that folder into the Flash UI\Themes directory
5) put the name of the icon-theme-folder into the themes.txt file in the following format:
Example themes.txt file (don't include the ---, just what is between the dashes)
<Theme name="Mario_by 32x"/>
You can put multiple lines in there too. just make sure you put it like this:
<Theme name="(title of icon theme folder)"/>
hope that helps.
If you want to use custom icons on the S9, you can either use claw's wallpaper UCI and have it replace all icons with an icon pack, or (using claw's or dnw's) you can add custom icons and just pick which icon name.PNG you want to use for either. if you are using Claw's, I can walk you through it a bit. if not, you'll have to ask around the AU thread.