The phrase "knocks together" implies the act of assembling or building something. Antonyms for this expression include disassemble, dismantle, take apart, break down, and undo. These words suggest actions that go against constructing or assembling something, instead, dismantling or taking it apart. Disassemble means to take apart or break down a structure, while dismantle means to take apart or disassemble something completely. Take apart is similarly to break something down into its component parts, while break down involves disintegrating something that was once whole. Finally, undo is to reverse the effects of assembling by separating previously connected parts.