Step 1: Select Manage Stream, either in the menu bar, or under your Today's streams list.
Step 2: Navigate to the sliding Audio button above the stream preview.
IMPORTANT: The graphics and audio toggle buttons can only be used once the service is live - i.e. while streaming is taking place. They cannot be used in advance of matchday, nor after the stream has ended.
Step 3: Clicking the sliding Audio button will grey out your audio and volume slider. Your stream has now been muted.
NOTE: The volume slider can also be used to increase and decrease your stream's audio on YouTube. Please be aware that muting or adjusting the volume here will not impact the audio in your preview.