Inside the Navigation bar select the "Course Admin". 

Under the Tools select "Rubrics" .

Click on the drop down icon located on the side of the "Rubrics" you want to edit. If no rubrics exist you can create one.

The Rubric must be in "Draft" status, edits are saved automatically.  Change the status to "Published" when you are ready to use it.

To add a criterion row, select the "+ Add Criterion" link.

To delete a criterion row, select the Delete button for the criterion row.

To add a Level, select one of the "Add Level" buttons.

To delete a Level, select the Delete button for that level.

select the "Options" drop down button to expand the "Options" menu to modify Rubric Visibility settings.