How do I change login wallpaper? Mac Sierra Beta I use to be able to change the login screen wallpaper on previous versions by going to /Library/Caches and then just pasting the wallpaper I want with this "com.apple.desktop.admin.png" as the file name. I've done it multiple times in the past and with this new macOS Sierra I am unable to do so. Anyone else find a new way where is it now. Where did Apple hide the files to do this? Has anyone discovered it yet?