How to update/upgrade Pi-hole with an OpenVPN on Ubuntu/Debian Linux server

Originally published at:

I installed an OpenVPN server with Pi-hole software to block block ads, reduced my 4G/3G/LTE traffic on the same Debian or Ubuntu Linux server. How do I upgrade my Pi-hole to the latest version using command line?

Linux sysadmin blog - Linux/Unix Howtos and Tutorials - Linux bash shell scripting wiki