Remove the manhole lid, compress the Speedplate to a diameter small enough to be inserted into the frame, adjust the hanger tabs if needed, expand the Speedplate and adjust the center in the frame, tighten the adjusting wheel so the Speedplate is secure in the frame.

Product Link: https://mrmanhole.com/product/leg-platinum/

Resource: https://www.youtube.com/watch?v=Lby3n6kD4eQ