There are various pages and forum threads with instruction on the net, as this hack also works in Vista. For exmaple
this.
The latest ResHacker version (from its original homepage) has 64-bit support, reelased a week or so ago. You'd also need to change the ownership of the dll to Administrator (and enable write access) so you can copy the modified dll over it. Always keep a backup of the original dll.
The dll file is normally in use (which prohibits replacing/modifying), so you'd have to kill the explorer.exe process before replacing it. There might be an easier solution to that, I haven't tried it though. Since the dll apparently has a separate version for Aero, it should be possible to switch theme to classic, replace the aero version of the dll and then switch back to Aero. Or if you use classic theme then switch to Aero temporarily to replace the dll.