def METHOD_NAME():
    uis = UserImage.objects.filter(image__disk_file__file_type='FITS image data')
    print(uis.count(), 'UserImages are FITS')
    for ui in uis:
        im = ui.image
        im.display_image = None
        im.thumbnail = None
        im.save()
    print('Updated', len(uis), 'UserImages')