If your file is being linked from a page, simply publish the page, which will automatically publish the linked file.
For an updated file (a file that has been altered since it was first uploaded), follow the tutorial below:
Select the file
Select the file directly in your system tree.

Publish
Once the file has been selected, click on the Publish tab.

Submit
The Publishing settings will be pre-determined for you and should not be altered. Click the Submit button to Publish.

A message will display that the publish has been sent successfully.

If your publish has successfully gone through, you will also receive a message on your Dashboard, which can be accessed by clicking on Home at the top left and then the Messages link.

If you are still having difficulty publishing, read our Publishing FAQs.