On the bottom of the OnHub is two screws holding the casing to the base.

To access these screws, you must remove the rubber pad that is glued to the base.

To remove the pad, slide a metal spudger under the edge of the pad. Pry the pad away from the base, removing the glue.

Once the pad is pulled up enough to grab, peel it the rest of the way exposing the screws.