Only a dataset's admins can edit or delete that dataset's pre-defined entries.
- Go to Admin > Manage Datasets.
- Edit your dataset.
- Click on the Manage Pre-Defined Entries tab.
- Click on the Edit () button in the Action column to modify the entry.
- Click on the Delete () button in the Action column to remove it. This won't affect any previously-entered data -- it will just prevent people from using it in the future.