1 - Click on the placard image with the right button of your mouse, or CTRL + click for MAC users.
2 - Save the image in a folder on your computer.
3 - Go to your facebook profile page and click over your profile picture. You'll see the Change Picture link. Click on it.
4 - On the right menu that pop-up, click in Upload a Picture.
5 - Choose your saved placard image and click Open
6 - Post What's on your mind? to share it with your friends.
It's DONE! :)