Its not ABS pin, its the wear indicator. Once the brake pad wears down to a limit, this pin will grind against the disc and create a metallic sound to warn you the brake pads are worn, time for a change.
i installed the last brake pads myself at home and this written material that came with them. It also had the shim plates and the grease sachet. Brake pads were Asuki ordered from PW online store. They have lasted me 30,000 km so far and still have 30-40% life yet. Im eye balling it so i'll keep a new pair handy the moment the wear pin is close to the disc, i'll change them.