Make a backup first
Before any update, back up files and database: with your host’s backup tool or a backup extension such as Akeeba Backup (free). Test big updates on a copy of the site first.
Update a template
- Download the new version from your account (Pro) or the template page (Free).
- Go to System → Install → Extensions and upload the template package, as for a new install. Joomla updates it in place.
- Your template style settings, menus, modules and content stay.
Changes you made inside the template’s files (CSS, PHP) are overwritten by an update. Put CSS in Template Options → Custom Code and layout changes in template overrides, which updates keep.
Upgrade Joomla (for example 5 to 6)
- Update your Joomla to the last release of its current major version first (System → Update → Joomla).
- Check that your template and extensions support the new major version (the rebuilt LTHEME templates support Joomla 6 (latest version); for a template not rebuilt yet, see its docs), and update them.
- Run Joomla’s Pre-Update Check, then the upgrade.
- Afterwards check the home page, the menus, the contact form and any shop pages.
SP Page Builder, Smart Slider, Convert Forms, SP Simple Portfolio and SP Easy Image Gallery have their own updates: update them from System → Update → Extensions.