if you mean the Project Lead of a given project - project settings > details and edit the Project Lead at the bottom of the page. Deactivate old user if desired.
if you mean you want to change the Jira admin - add the new user to the admin role (jira settings > user management) and deactivate (don't delete) the user that departed. Note if there are automations, etc. that the previous admin had attached to their user you should modify these before deactivating them.
Learn how to use two new reports for next-gen projects in Jira Cloud: Cumulative flow diagram and Sprint burndown chart. Ivan Teong, Product Manager, Jira Software, demos the Cumulative ...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events