I just upgraded my Moodle install to the latest and greatest which is version 1.9.7. But first I had to backup my files ..
I backed up the moodle directory ,the moodle data directory and also the mysql database. I then switched the site to maintenance mode so that only the admin which is me ,can login .After that I just did a:
sh$ cd /var/www
sh$ tar xvzf moodle-archive.tgz
sh$ chown -R www-data:www-data /var/www/moodle
I then login to the site as admin and just follow all the instructions. That’s all there is to it. 😉