|1-Pry off the white hole cover, lower right
|2-Place the base over the pre-threaded hole
|4-Insert screw in Allen head bolt
|5-Tighten with #4 Allen wrench, say a bazillion Torque Foot-Pounds or so.
OK, I exaggerated. Only a thousand Foot-Pounds should do it.
|Ready for Head and Neck Restraint
(Oh, and remember to do the other side too!)