How to Change Stubborn Icons

Understanding ICNS files is the secret to fixing those icons that just won't change.

Warning: Before you modify or replace the ICNS make sure to create a backup of the application you're modifying. If you follow these instructions, you do so at your own risk.

If you've run into an icon that just won't change the using traditional methods, and it's not a system icon, then you're probably trying to change the icon on an application with an internal ICNS file. ICNS (.icns) is the Mac OS X propritery file extension for an icon resource. It works like the .sit file extension on Stuffit files, or the .app file extension on an OS X application. ICNS files don't work like traditional icons in the sense that their custom images are stored inside the files as data, not displayed on the outside of the file as an icon. You'd have to open up a ICNS file to see the icon images inside.

ICNS file are stored inside of applications. Some applications are programed to call upon specific ICNS files when they start up. If you try to use the old copy & paste method on application icons such as Mail.app, System Prefs, or Safari (just to name a few) you'll find that when the application starts up it will change back to its default icon. In order to change these icons permantently you need to replace their ICNS files.

The first step to changing an ICNS file is finding it. To do this you'll need to open up the application and get into the Resources folder.

To do this control-click on the application in the finder. A contextual menu will pop up. Select "Show Package Content". If you do this correctly a window will pop up that have a folder named "Contents" inside.

Open the Contents folder and find the folder named "Resources". Resources will have a bunch of files inside. One of them will be the ICNS file you are looking for. Their may be quite a few ICNS files in any particular application, so make sure you pick the right one. You can test them by viewing them with Apple's Preview.app. The correct ICNS will look just like the main icon.

1. Locate the original ICNS file in the application's resources as explianed above.

2. Pick a new icon that you want to replace the ICNS file with.

3. Convert the newicon to an ICNS icon file. The easiest way to do this is to use the program Icon2icns which is available for free at ittpoi.com.

4. Rename the new ICNS file to match the name of the ICNS file in the application.

(application): Contents: Resources: *iconname*.icns

5. Replace the old ICNS file with the new one. Some applciations may require that you change the permissions on the application's Resource folder before you can replace the old ICNS file. Use caution when changing your permissions and always change them back when are finished.

6. Restart the application and the ICNS should automatically apply as the main icon. If the icon still changes back after you quit the application you may need to apply the icon using the copy and paste method as well.