Preview the script first then ...
- Copy-paste the install file in a new bash file and run it
or
- Run this in the console to download the file in the current folder and run it
wget -O "./install-docker.sh" "https://raw.githubusercontent.com/docker-how-to/install-docker-on-ubuntu-16.04-plus/master/install.sh" && chmod +x install-docker.sh && ./install-docker.sh