# Open synaptic and install :
# gdm 2.20.11
xdmcp remina remina-gnome gdm

# Next open Alt+F2 gksu gdmsetup
# if you can create menu launcher in KDE, right-click the system menu click edit-aplication,
#choose your directory pressing on the main menu to the directory right menu

New item
Item name : Gdmsetup
Comand : gksu /usr/sbin/gdmsetup

# Open gdmsetup click 'Add' move to file system /home/user_name/downloads and install