These icons are made specifically to replace the default icons in the third party AIM client Adium. To install the icons drag all three of them into the Dock Icons folder. The folder can be found here:

/Home/Library/Application Support/Adium/Custom Files/Dock Icons/

Then go the prefrences in Adium and select the Icons.

A replacement Away Graphic is also included. Installing this is more difficult. First find the Adium application and ctrl-click (right click) on its icon. A menu will pop up. Select, "Show Package Contents." Open the "Contents" folder and then open the "Resources" folder. Now find the file named "overlay_away.tiff" and ctrl-click on it and select "Duplicate." This makes a copy so you can go back to the old away graphic if you want to. Then drag the "overlay_away.tiff" file from the Adiumotion folder into the "Resources" folder and click replace. Restart Adium and when you are away instead of the sign the chat bubble will display "Away..."