I am brand new to Ubuntu (and linux for that matter). I bought an old computer and with the help of a friend installed ubuntu, but the hardware is a little too slow for gnome. He suggested that I install a "lightweight window manager" and pointed me towards xfce. apparently he downloaded it using synaptics but I dont know how to actually change my default manager from GNOME to xfce.
If anyone could give me the complete noob's guide, that would be fantastic. you can assume I know NOTHING about anything. lol