Place the wire mute on top of the strings and in front of the bridge. The metal piece with the three pieces of cork should be facing towards the neck, while the brace should be facing towards the bridge.
Widen the two metal braces of the mute by placing your thumb and index finger between the braces and pressing them apart. This will widen the slit in the middle of the mute and allow you to slide the mute onto the strings.
Place the D and A strings between the metal braces and release your fingers to affix the mute over the strings.
Slide the metal brace up and over the bridge when you are ready to play muted. When not in use, you may remove it or slide it back down the bridge towards the neck.