1.Log in as admin and navigate to Site admin>Plugins>Text editors>Manage editors.
2.Unhide the Atto HTML editor by clicking the eye icon.
3.Use the arrow icon to move it to the top of the list.
4.In a course, with the editing turned on, add a label and verify you see the Atto HTML editor (http://docs.moodle.org/dev/images_dev/3/3a/Atto26.png)
5. Navigate back to Site admin>Plugins>Text editors>Manage editors.
6. Use the arrow icon to move the TinyMCE editor to the top of the list.
7. In a course with the editing turned on, add a label and verify you see the TinyMCE editor (http://docs.moodle.org/dev/images_dev/5/52/TinyMCE26.png)