Updating Drupal Themes and Modules

By Lynn Beighley and Seamus Bellamy from Drupal For Dummies, 2nd Edition

Suppose you want to upgrade a Drupal module or theme you’ve installed. The Available updates page in the following illustration shows any modules that are out of date, along with the link to download the new version right there on that page.

To upgrade a module or theme, follow these steps:

Click the Modules link (or the Appearance link, if you’re updating a theme).
Scroll to the bottom of the page and deselect the Enabled check box next to the module, or click the Disable link next to the theme.
Click the Save Configuration button.
Find the old module or theme to be upgraded on the web server using some kind of file manager program.

This may be through a control panel on your web host's site. If you’re comfortable using FTP, it will also work. For example, a module called Author Pane would be located in the Drupal directory at sites/all/modules/authorpane.
Back up these old files by copying them to your desktop computer.

The idea here is that you want to keep a copy just in case something goes wrong with your upgrade so you can restore the old files.
After you make a copy of these files, delete the ones on your web server.

Be extremely careful that you delete only the files inside the folder of the module or theme you’re upgrading.
Delete the now-empty folder on your web server.

For example, the authorpane folder was deleted.
If possible, follow the steps in the “Automatically installing modules and themes” section. If you can’t install automatically, use the “Manually installing themes and modules” sections.