I had the impression they were designed to break-away. With enough "pull", the rings would snap apart.
I just put the black plastic lanyard rings on two of my L1s that did not have them on when I bought them. They just snapped together to install.
I figured you would just run the cord of the lanyard directly through the loop for the clip, and pull until it snapped off.
Now I wonder!
From Surefire web site...
"Z60
Includes both a lanyard and lanyard ring. The lanyard is made from gray 550 parachute-cord and is equipped with two cord locks and a cord fastener. For safety, the fastener is designed to break away if the lanyard or light is pulled on with extreme force. The polymer lanyard ring fits the groove in the flashlight tailcap."