To install Joomla, there are four main steps: 1. Download the Joomla files from the Joomla website. 2. Place the files on a web server or local disk. 3. Configure the Apache web server. 4. Create a database and install Joomla using a wizard. The document then provides details on configuring the Apache HTTP server, including pointing the document root directory to the Joomla installation directory and settings for options, overrides and access control.