The swivel kit includes:
4 plastic washers
4 metal washers
Bottom cover plate with 4 (3mm x 12mm) screws
Rotatable ring with 4 (4mm x 10mm) screws

Unscrew and remove the rubber feet of the stand.

With the stand upside down and level, position the plastic washers over the screw holes.

With the stand upside down and level, position the plastic washers over the screw holes.

Screw the cover plate onto the bottom using the 3mm x 12mm screws.

Position the 4 metal washers over the 4 inner screw holes of the cover plate.

With the metal washers in place, screw the rotatable ring onto the bottom cover with the 4mm x 10mm screws. The ring should be flush with the washers.

The installation is complete.