Hold two pieces together at inner radius and move socket up against the ball´s wedged end. Push until a klicking sound indicates a secure fit of socket onto the ball.
(chain section exposed for the purpose of demonstration)
Detaching: TRE.70 - TRE.85 - TRE-100
Insert screw driver into the opening of the socket from the top. Then twist apart, counter-clockwise.
Detaching: TRE.30 - TRE.40 - TRE.60
Bend triflex® into its radius and twist apart, counter-clockwise