Use the Custom Table Manager
1. Select Applications > Custom Table Manager
2. Select the list to be edited, and click Edit
If you wish to delete the custom list, click Delete - This action cannot be undone
3. Make any desired changes to the list in the table - You can edit values directly, or select a cell and press Ctrl+V on your keyboard to paste in a list of values
4. (Optional) click Validate Entered List to ensure all values entered are valid
5. Check Replace to replace the existing list, then click Save