Both types of frames mount the same way to the main frame.
To replace one assembly with the other:
1. The silver mechanism that locks the lateral feature is called a mechlok. Remove the shoulder bolt securing the mechlok to the lateral pivot frame. (It is located in the center of the picture.)
2. The lateral frame pivots on a 7/8” chrome rod also located near the center of the picture. To remove it, loosen the two set screws on the back of the collars that hold it. Tap the top of the 7/8” rod to remove it while you support the weight of your head frame.
3. The new head piece is attached by inserting the 7/8” rod and attaching the mechlok.
