Instructions
Wired headset
Connect the headset plug to the expansion port on the bottom of the Xbox 360 controller.
Change the volume level by rotating the volume control knob.
Press the "Mute" button to stop transmitting your voice. This does not stop you from hearing others.
Wireless headset
Connect the AC adapter to the bottom of the wireless headset and connect the opposite end to a power outlet. Let the wireless headset charge until all four lights on the headset are blinking (indicating a full charge).
With the console turned on, press the "Power" button on the headset.
Press the "Connect" button on the Xbox 360. The lights on the console and wireless headset will flash for a few seconds and stabilize. This is confirmation that the headset is connected. Press the "+" and "-" buttons on the wireless headset to adjust the volume. Press the "Mute" button to stop transmitting your voice. This still allows you to hear others.