Attach a Ball Joint Arm to the ball joints on the carriage as shown. As you press the socket over the ball on the carriage, you'll hear a faint "click" as it locks into place.

Attach the Ball Joint Platform you assembled previously to the other ends of the arms as shown.

If you're using a hot end other than the older one shown in this guide, you may want to install the effector platform with the ball-arms facing up. This will provide additional clearance between the effector platform and the heated bed, which is required by some hot end designs like the HE280 or E3D v6.