Editors & Commenters can leave a project (while maintaining access to it) in order to clean up their workspace.
Guest Editors & Guest Commenters may leave projects at will, but will need to request access from a Billing Manager to join those projects again.
From the Projects page, click the kebab menu on the project you'd like to leave.
Click the 'X' to the right of your name to remove yourself from the users with access.. (You may have to scroll to see your name if there are several other users in the project.)
This project will now be listed below the projects you have access to.
Made a mistake? Need to access one of these projects again? No problem.
Just click 'Join Project'.