ok - well upon looking again i'm wrong. it doesn't attach to the press part, it's a whole new upper arm design. which seems to jut straight out from the upper surface of the arm... ehhh. sound like a part that will bread a lot. i might just get a razor saw and cut it off.
Pretty sure it's just a bog-standard 5mm adjuster that has been screwed into the top arm with a screw on the underside. Don't think the arm has been modded, that would have added unnecessary production costs.