How to Change Your Mac Icons
This how-to article is about changing you Mac icons. It goes into detail on how to make your dock icons a different image, like your favorite sports team or just a cool looking image.
Choose an image you would like to use. When searching the image in Google, make sure that it is in .png format.
After selecting the image you want, save it to your desktop. Then open it up in Preview.
In order for the logo to appear in a circular form, like Google Chrome's icon, you need to crop it. You can do this by selecting the crop tool and clicking on elliptical selection. After you have cropped your image, go up to edit and select inverse selection. Now you can click delete.
Next choose the icon you want to show your image and press control and click on it. Then go up to options and then click on "Show in Finder". Control-click on the application you want, and select "Get Info".
Now go back to your image and select all and copy it. Then click on the icon until you can see a faint highlight of blue around the edges and paste your image. If the application is currently running, quit out of it before it can work.