trinity kde sudo

I followed the advice of Timothy Pearson  to add secure_path=/usr/local/sbin:/usr/local/bin:/opt/trinity/sbin:/usr/sbin:/opt/trinity/bin:/usr/bin:/sbin:/bin:/usr/X11R6/bin to the /etc/sudoers.d folder and when i run sudo anything is says sudo: /etc/sudoers.d/trinity is mode 0644, should be 0440  how do i set it from 0644 to 0440