How to change the osx lion login wallpaper

This will show you how to change the login screen wallpaper background image in osx lion.

the file you need to change is called


/System/Library/Frameworks/AppKit.framework/Versions/C/Resources/
NSTexturedFullScreenBackgroundColor.png

simply rename the image and copy the image you want to the folder and call it


NSTexturedFullScreenBackgroundColor.png

done :)