Step 1. Login to your course and navigate to the Grades from the Navigation block. 

Step 2. From anywhere inside the gradebook, you will need to click on Letters at the top of the page. 

Step 3. Click on Edit or Edit grade letters both go to the same edit screen. 

Step 4. You must place a check in the box for Override site defaults before the system will allow you to change the percentages. Enter the lowest possible percentage for the letter grade. Please remember to leave “F” at zero. Save Changes at the bottom of the page when finished.