This includes one set (two pads) of replacement anti-slip pads for the Bookfellow and the Curiously Heavy Book Weight. 

Installing a new pad is generally a straightforward procedure. The old pad is simply pulled off and a new one stuck on. Any adhesive residue should be removed as best as possible, usually by dabbing the adhesive side of the old pad to pull up any remaining adhesive. Do not use any dissolving cleaners to remove leftover adhesive.