For reference: The "back" of the cushion is closest to the seat cushion.
IF ADDING SNAPS AND COVER (cushion is off the table)
Center the screw snap on the 3/4" plywood which is approximately 3/8" from the bottom of the cushion.
Screw the snaps into the wood slowly to prevent the heads from tearing through the vinyl.
When attaching the cover to the foot cushion, attach the front snaps to the foot cushion first.
Pull the plastic cover over the top surface of the cushion and snap the last two. It will have to stretch to do this.
IF REPLACING COVER ONLY (cushion is on the table)
Snap the back snaps to the foot cushion first. Note that the back snaps are a little closer together than the front ones.
Pull the plastic cover over the top surface of the cushion and snap the two on the front side. It will have to stretch to do this.