Remove the hex screw from the tension knob and set aside for later use.
Discard the factory chassis as it will not be used with the replacement mount.
Keep the washers, the rod, the knob screw and the rod pin for later use.
Grease both sides of the round washer and the post then replace washer as shown here.
Insert the new mount. Pay attention to the left/right orientation of the speed lever.
Grease the front/bottom portion of the mount and then replace the slotted washer as shown here.
Take the rod pin and insert it into the rod as shown here.
Replace and seat the rod & pin through the post and atop the slotted washer as shown here.
Place your thumb over the rod & pin to hold it into place while flipping the bipod over. Now install the new LaRue knob and tighten in place with the factory hex screw to the point that the knob can only be turned 1 full rotation from the tightened position.