Install these Icons or any icons on your SD card into a folder named Icons ,You use ADW or Launcher pro , Long press an icon on your home screen , Select change icon , custom icon , then choose the correct icon from your gallery
This will only work for you dock.
With better cut (paid app) you can just long press the home screen, shortcut, better app, installed application, pick the app, rename the app title (for home screen) change the icon, pick picture, navigate to the picture, and your done.