• Android: Play store, F-Droid, Sources
• iOS
• PC/Mac

• Config directory: /home/${USER}/.local/share/data/ownCloud/

Assuming that your webserver runs with www-data user

cd <YOUR_WWW_ROOT>
sudo -u www-data php  owncloud/occ maintenance:mode --on
sudo -u www-data mv   owncloud owncloud-old
sudo -u www-data wget "https://download.owncloud.org/community/owncloud-latest.tar.bz2"
sudo -u www-data tar  xjf owncloud-latest.tar.bz2
sudo -u www-data cp   owncloud-old/config/config.php owncloud/config/config.php
sudo -u www-data mv   owncloud-old/data owncloud/data
sudo -u www-data php  owncloud/occ upgrade
sudo -u www-data php  owncloud/occ maintenance:mode --off
sudo -u www-data rm   owncloud-latest.tar.bz2
sudo -u www-data rm -Rf owncloud-old

if needed remember to restore your applications and/or themes.

1. Add a suffix to your existing owncloud folder or move it away
2. Upload to your server latest owncloud version
3. Move back “data” and “config” folders from previous installation to the newest just uploaded