You must be logged in as admin to do this.
Updating Drupal Core
1. Take site off-line:
/admin/settings/site-maintenance
2. Take back-up of MySQL database:
/admin/content/backup_migrate/export/quick
3. Get latest version of Drupal core.
3.1 Download latest version from
https://www.drupal.org/project/drupal
to a local folder, e.g.
C:\users\andrew\drupal
3.2 Untar / unzip downloaded file
(Need FTP client e.g. Filezilla for the following steps)
Connect FTP client and go to website root folder (currently /httpdocs).
4. Take back-up of current version of core. In website root folder:
4.1 Create new folder, e.g.
/2015_01_24_Core_Backup
4.2 Move all Drupal related folders and files - EXCEPT for 'sites' folder - from root folder to core backup folder
You can tell which are the Drupal related files/folders by comparing with what's in the new version of Drupal core from the previous step.
There are a few folders e.g. 'logs', 'plesk-stat' that are to do with the web-hosting. These should be left alone.
5. Using FTP client copy all files/folders EXCEPT 'sites' from new version of core on C: drive to website root folder.
(From web browser)
6. Run /update.php
7. Put the site back on-line:
/admin/settings/site-maintenance