The Documents tab of Maintain Events allows you to attach any number of documents to an event.

These documents may be viewed independently of any event by going to Calendar → Event Documents.

This list will not include any documents for which the title contains the word "Agenda" or "Minutes" unless the current user is a site administrator or has a user role that is authorized for the "Maintain Agenda and Minutes" task or the "View Agenda and Minutes" task.

Click on the document name to open that document.  Click the Update button to go to the page shown below.

The Event drop down list allows you to link this document to a different event.  This should only be done if the document was accidentally uploaded under the wrong event.

The Document type is "File Upload" for files that have been uploaded to the TroopWebHost server.  "URL link" allows you to reference files on other servers using a URL.

You can change the Document Title to make it more descriptive of this document.

If you wish to replace the file that was uploaded, put checkmark in the Delete box, then click Save & Exit.  This will delete the original file.  Then update this entry again, and use the Choose File button to select the new file.  Click Save & Exit to upload the new file to the server.