This tutorial will show you how to upgrade your old/outdated version of Xibo to the current version available. These instructions are for Linux (I am using Ubuntu Server 20.04.4 LTS and Xibo 3.04) with Docker-Compose.
The commands that I am using will be red.

Step 1: SSH into your Xibo display server.

Step 2: Change into the /opt/xibo directory by using:
cd /opt/xibo

Step 3: View the contents of your directory to see if you still have a leftover installation package by using:
ls

Step 4: If you already/still have xibo-docker.tar.gz in the directory, you will want to delete it now by using:
rm xibo-docker.tar.gz

Step 5: Now we will get the link the most recent version of Xibo via their GitHub page, which can be found by going here: https://github.com/xibosignage/xibo-cms/releases – you want to get the link for the most recent version of xibo-docker.tar.gz – right-click on it and copy the link.

Step 6: We will now download this file in your SSH terminal by using:
wget https://github.com/xibosignage/xibo-cms/releases/download/3.1.1/xibo-docker.tar.gz
(replace that link with the current version! 3.1.1 is the current version for me RIGHT NOW)

Step 7: Now we want to un-tar the file by using:
tar –strip 1 -zxvf xibo-docker.tar.gz

Step 8: We will now take our current Xibo/Docker instance down by using:
docker-compose down

Here is a screenshot with all of the commands that I have used so far, circled in red:

Step 9: Now we will bring the Xibo server up by using:
docker-compose up -d

We are now finished! Give it roughly a minute or so and you will be able to connect to the web-interface for your Xibo server. 🙂