I'd like to change the icon of a program called Refit with a custom one. This program has various tools and when I try to change those icons all is ok but then I run the following command:

$ locate refit.icns

and the output is:

$ /efi/refind/icons/os_refit.icns

The problem is that I don't have any folder called refind and the path simply doesn't exist. I tried it with both:

$ ls 

and

$ sudo ls

in the /efi directory. So my questions are actually two: how can I change the icon of that program? And why there is this strange behavior with the locate command?

I'm on Snow Leopard 10.6.8. Thanks for your help.