admin of a facebook group with 250+ members how to change the privacy settings to secret?

[Piyush]

I am an admin of 789 members I am fed of trying to make the group secret. There is no option to make it secret in group settings please help me.

[Mrs.Draco Malfoy]

Go to the group page.
In the top right corner just under the big group photo is a little wheel thingy.
Click it and choose 'Edit Group' from the drop down menu.
You will then be on the settings page.
Under the heading 'Privacy' there are 3 options.
Click on 'Secret'.

Hope this helps!