With the abundance of icons in the upper right corner of the Mac OS X screen, it could be time for a change. If you’re tired of the same old Notification Center icon–the one that looks like a bullet list–this tip’s for you.
To start, open your main system Library folder. You can use the Go To Folder menu in the Go menu in the Finder. Or you can hit Command-Shift-G to bring up the same Go To Folder field. However you choose to do so, type or paste in this path: /System/Library/CoreServices/ and then scroll down to Notification Center. Right click on it and select Show Package Contents.
Open the Contents folder, then the Resources folder. Find menuitemNormal.tiff and copy it. Click out to your Desktop folder and paste it as a backup. You can Option-Click and drag it out to the desktop, or just hit Command-C and Command-V like you would any other file or text you want to copy and paste.
Now, either open the TIFF file and modify it in any image editor, or create your own 54 X 44 pixel image to suit your whimsy. I grabbed a picture of the 1Up mushroom off of Google images, and resized it in Preview to 54 X 44, with a resolution of 72 pixels per inch.
Now, head back to the package contents folder and delete the menuitemNormal.tiff file. Save this new file in the same place, renaming it menuitemNormal.tiff. If you need to make it a TIFF file, use Preview or just rename in the finder. You’ll need to enter your administrative password for each step, when deleting, moving, or renaming the file.
Now relaunch the Notification Center process. Open your Utilities folder and find Activity Monitor. Launch this app and find the Notification Center process in the list. Click to select it, then click on the Quit Process icon (it looks like a stop sign) in the upper left. The process will quit and restart, adding your image to the top corner of your screen.
If you want to reset the icon back to the default, simply do the steps again, but this time, put the original file you copied and pasted to your desktop in the Resources folder for Notification Center. Kill the process in Activity Monitor, and you’ll be all set.
Thanks for the tip, Mithilesh!