LXLE utilizes automatic security updates and installation by default; doing so in the background during idle time.

All other updates are performed by synaptic package manager located in

Menu>System Tools>Synaptic

• Click Reload
• Click Mark All Upgrades
• Click Apply
• Mark Additional (if needed)

To save memory there is no update “checker” daemon running in the background.

To upgrade to a new release of the core components of the operating system the following tutorial works fine.

http://lawrit.lawr.ucdavis.edu/it-help-center/how-to/upgrading-ubuntu-via-command-line

*Note upgrading to a new release will simply upgrade the core components on older machines I tend to either not upgrade to the new LTS release or if I do to do a backup of my files and complete reinstall.