I goofed! I was trying to add the system tray to my panal so HPLIP would quit giving me an error every time I boot. I added what I already had, and was unable to delete it. So I tried removing the panel so I could replace it clean and start over. Unfortunately, there is nothing but a trash can on my desktop so all I could do is press alt-ctrl-del to get an option to log out.
Is there a way to add the panel back to Gnome Classic when all I have is the desktop and a trash can?