That video was for older version of Joomla so will not help. But it can be done from Global Configuration. For advance, you can use SH404 component
Please go to Joomla back-end *Navigate to "Site" >> "Global Configuration" *We want to set Search Engine Friendly URLs to Yes *If you are on an Apache server that uses mod_rewrite set this option to Yes, otherwise leave it to NO *Then save the changes *The configuration changes have been made. If you are using apache with mod_rewrite there is one more step, updateing the .htaccess file. *Open the htaccess.txt file *If you have joomla installed in a folder (eg: http://example.com/joomla) you will need to edit the RewriteBase line. It should read RewriteBase /joomla *Save the file *Then rename htaccess.txt to .htaccess