I originally had Kubuntu, then changed to Lubuntu from the command lines (Ctrl+Alt+F6) and then changed again to Ubuntu from the command lines and I am now running Ubuntu 18.04.1, but am still seeing the Lubuntu desktop.
I really dislike the desktop, want to completely remove all three systems and their packages and start completely anew with Xubuntu. I have a bootable usb ready to go, I just don't know how to boot it and from where. I'm very lost in the Lubuntu desktop. I ruined the CD compartment on My Toshiba Satellite, so I can't use a CD to run the .iso file.