How do I install a WTMLC-A Series watertight well cap?

INSTALLATION INSTRUCTIONS

WTMLC-Axx SERIES - ALUMINUM TWO PIECE WATER-TIGHT / VERMIN-PROOF WELL

1.
Take the smaller diameter well casing O-Ring and stretch it over the well casing keeping it flush with the top of the casing.(Step #1)

2.
Place bottom ring of the well cap with set screws fully retracted, over O-Ring. Failure to retract all set screws may result in cutting the O-Ring. Push down on bottom ring, O-Ring will roll inside the ring, until the top of the bottom ring is flush with the top of the casing. (Step #2)