LDAP on MC

Hi,

I am trying to setup LDAP authentication to Management console.

I had already installed MC and now I am changing the authentication to "Use LDAP Authentication" I fill in the details and click verify, it succeeds.
Going ahead I apply the changes, it says " Removing LDAP authentication will cause all users to use password" I am a bit confused on this. If I am changing the authentication to LDAP why does it say so.
Once I press OK and then press the done button. I am back to MC home, but when I check the Authentication tab in MC Settings its not using LDAP.

Strange that I could not find anything on changing the LDAP authentication after MC install.
I found the documents pointing out "Selecting Authentication while installing and configuring the MC"

Is it a known fact that the Authentication can only be configured while configuring MC for th efirst time ? Or I am missing a big chunk of it ?

Thanks