There are few programs to change your icons easily with a few clicks, but as i think people do not change their icons everyday it’s kind of a useless thing to give money for such things. Either way you can do it to yourself. I cannot take any responsibility for the damage may caused to your computer, but this works for me.

As we know changing icons for simple programs, like Safari, iTunes, Mail etc., it’s just an easy Get Info → Copy & Paste thing. But the changing of our Finder icon pretends to be a headache. So let’s see how it works!

First, you’ll need your desired replacement icon in a .png & .icns format. If you haven’t got any idea how could you get these file formats, please use this website, easy as pie to convert!
Go to your Mac’s Library, like System → Library → CoreServices → Finder.app and Right-click “Show Package Content”
In this folder go to Contents → Resources → Finder.icns and replace it with your desired icon’s .icns formatted icon with the exact same name like “Finder.icns” (maybe administrator’s permission needed). PLEASE RESTORE the original Finder.icns somewhere on your Mac.
Okay, we’re almost cool now. Go to System → Library → CoreServices → Dock.app and Right-click “Show Package Content”, then go to Contents → Resources again. Here you’ll find the “finder.png” image, PLEASE RESTORE FIRST, then replace it with your icon’s .png formatted picture.
The next step is a really important step. You have to delete your dock & finder “history”, unless your old Finder icon will be shown.. BUT this may cause that you have to set up your Dock and Finder’s view options – but it’s not really a hard thing to do. So, go to Users → You → Library → Preferences and find “com.apple.dock.plist” and “com.apple.finder.plist” files. PLEASE RESTORE them, then delete.

Now, you’re done – Do a restart and voilá! But don’t forget you have to rearrange and redo your Dock and Finder settings!
If you’ve found this post a help to yourself, please share!