To change folder icon in Mac OS

1.      Open folder with Mac icons in .ICNS format in Finder and copy icon (Cmd+C).

OR

Select a folder which has different icon then default icon for folder in Mac

1.1  Get folder info for the folder.

1.2  Select folder icon and copy the icon through “Edit/Copy” from Desktop top menu.

2.      Now get folder info for the folder you want to change icon.

3.      Select folder icon and paste the icon through “Edit/Paste” from Desktop top menu.