How do you change the mac finder icon on mac os x el capitan?

To change the Finder icon on macOS El Capitan, first, find an image you want to use as the new icon and copy it (Command + C). Then, open the Finder, select "Applications," find and right-click on "Finder," and choose "Get Info." In the Info window, click on the small Finder icon at the top left, and paste the new image (Command + V). Finally, close the Info window to see the updated icon.