Warning, this is not an official guide!!! 1. sudo mv /etc/apt/source.list /etc/apt/source.list.bak 1a. Create new Source.list sudo nano /etc/apt/source.list 1b.  insert (for Debian Stretch) 1.2B (for Ubuntu Cosmic)   1c.  sudo apt update && sudo apt dist-upgrade && sudo apt autoclean && sudo apt autoremove 1d.  sudo apt install curl wget apt-transport-https dirmngr git software-properties-common Now you can start setting