From Kubuntu to Ubuntu

Steps:

• sudo apt-get install ubuntu_desktop
• change display manager to lightdm as described in Change Linux display manager
• change lightdm greeter theme as described in Change lightdm greeter theme
• set ubuntu boot splash screen:
• sudo update-alternatives --set default.plymouth /lib/plymouth/themes/ubuntu-logo/ubuntu-logo.plymouth
• sudo update-alternatives --set text.plymouth /lib/plymouth/themes/ubuntu-text/ubuntu-text.plymouth