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. Log in as a teacher and go to Administration>My profile settings>Edit profile.
4. Scroll down to Text editor and select Atto HTML editor. Click 'Update profile'.
5. 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)
6. Return to Administration>My profile settings>Edit profile.
7. Scroll down to Text editor and select TinyMCE editor. Click 'Update profile'.
8. In a course with the editing turned on, add a label and verify you see the TinyMCE HTML editor (http://docs.moodle.org/dev/images_dev/5/52/TinyMCE26.png)