This article teaches you how to change your event's privacy setting from “Private” to “Public.” While you can't change the event's privacy settings, you can copy the event (and its invitees) and choose a new level of privacy.
Step
Step 1. Go to https://www.facebook.com via a browser
You must use a computer browser to use the methods in this article.
If you are not logged into your account, enter your username and password in the upper right corner of the screen, then click Enter or Login.
Step 2. Click Events or Events
It's in the left pane under the “Explore” or “Explore” heading.
Step 3. Click the name of your event
Step 4. Click
It's to the right of the “Edit” button below the cover image.
Step 5. Select Copy Event or Duplicate Event
A new event window will appear.
Step 6. Select Public Event from the drop-down menu
It's in the upper-left corner of the event window.
Step 7. Enter additional details and click Create
All guests you have invited will receive an invitation to a new public event.
