Server Administration > Item Fields > Deleting Fields > To delete a field in the GUI
  
To delete a field in the GUI
CLI EQUIVALENT 
im deletefield
1. From the Fields view, select the field you want to delete.
2. View the field, and examine the References tab to ensure that there are no references to the field.
3. Return to the Fields view, and with the field you are deleting selected, select Field > Delete. The Confirm Delete Field dialog box displays.
4. To confirm field deletion, click Yes.