1. Back up your Confluence instance

2. Choose Download to export data from each calendar using the old Confluence  Calendar Plugin to back it up
   
   You'll have a .ics file for each calendar after you complete this step.
    

   To help you identify all the places where Calendars exist in your system, you can run this SQL:

   SELECT 	CONTENT.SPACEID, SPACES.spacekey, SPACES.spacename, CONTENT.CONTENTID, CONTENT.title, CONTENT.LASTMODDATE
   FROM 	CONTENT, BODYCONTENT, SPACES
   WHERE	PREVVER IS NULL AND
   	(CONTENTTYPE = 'PAGE' OR CONTENTTYPE = 'BLOGPOST')
   	AND CONTENT.CONTENTID = BODYCONTENT.CONTENTID
   	AND SPACES.spaceid=CONTENT.spaceid
   	AND BODYCONTENT.BODY like '%{calendar%'
   	ORDER BY CONTENT.LASTMODDATE DESC

3. To Remove the old Confluence Calendar Plugin, choose Browse > Confluence Admin > Manage Add-ons and enter 'Calendar' in the Filter Visible Plugins field
4. Expand the 'Calendar' add-on entry and choose Uninstall to remove it from Confluence
   Note: Any existing pages set up to use the old calendar plugin will no longer work, as the Team Calendars plugin replaces it and has a different syntax
5. Follow the steps at the beginning of this page to install and activate Team Calendars
6. To re-import your old calendar data from your backed-up .ics files:
   
   1. From your dashboard, choose Calendars
   2. Choose Add Calendar at the top-right of the page, then choose Import Calendar
7. Choose the .ics file that you saved when backing up your old calendars.
   Repeat this step to add each calendar back into Confluence. 

Your old Calendar data will now display in the Confluence Calendars page.