Change default sidebar icons in finder when folder location changed...

Hi,

If I change the default Documents or download folder say if i move them to my other drive.. and add them back into the sidebar, I'm unable to change the icon to the standard Download or Documents icon.. anyone know how to do this please? I know its pretty trivial but would be nice to have back looking as it was designed..

FYI, I dont want to move the whole User profile over from the boot drive, just the Downloads and Documents folder..I want to keep pics and music where they are..

Thanks!

Kev