Currently you can only update this information from within the Raiser's Edge Database View.
  1. Log into Raiser's Edge Database View
  2. Open the constituent record you wish to modify
  3. Click on the Prospect Tab
  4. Click on Ratings
  5. You should see the Blackbaud NXT Rating there, just find the category you wish to edit
Note: that this information is updated automatically based on your Blackbaud NXT Ratings subscription, so any changes you make may be overwritten.