As an project admin or owner, you can access the Project Settings and delete a project. To do this, simply access SETTINGS on your selected project and click on the Delete this project link. You will be asked for confirmation. Before doing this, you might want to backup your project locally. To do that, go to SETTINGS > EXPORT and click on the EXPORT button. You will receive an email with a link to download a compressed project file. You can reimport this file during a project creation wizard.