GTK file dialog in KDE4


I have a problem with File dialog GTK used eg. by Chrome. In the past I set to this dialog links to favourite folders which are shown in the left column.

But now the folders (in real file structure) are changed, renamed, deleted etc. so I want to change or rename also the links inside the dialog.
Normally I suppose it should work by marking the folder and in bottom of the dialog is plus, minus to modify it. But it is always inactive and I cant see the way how to change it.

Please, any suggestion?

Thank you,