How to Mute/Un-Mute the conference by Admin

Hi All,
I have created the conference by using Admin and User pin.
When Admin joined the conference, how admin can mute/Un-Mute the entire conference by pressing *5?
If participant will join by his pin, how participant can mute/Un-Mute the his line in conference by pressing *6?
What are ways to do this?
Is there any other ways to do this?
How it will be done in the FreePBX?

Please help me to do this.

Waiting for positive reply.

Thank you.