I have tried following some simple steps in order to change my app icons, in which I go:
right mouse click on icon >> Click the little icon at top corner >> click edit then copy >> go to app icon and go get info >> click on the icon this time and paste it.
When I try to do this method, I find out that every icon I downloaded, the little icon at the top left corner has changed to the default "preview" icon with the letters ICNS. Why might it do this? Or is it maybe that this isn't the best way to accomplish icon changing in mac. Thanks for the help by the way!
Oh and sorry for asking a question like this, it is just that I'm new to OS X and I am not sure on how to do this simple task. Thanks again.