БРАТЬ/ВЗЯТЬ (ХВАТАТЬ/СХВАТИТЬ) БЫКА ЗА РОГА collVPsubj: humanfixedWO
to take bold, resolute action, immediately and bravely addressing the most essential, difficult aspects of the matter
X взял быка за рога = X took the bull by the horns.
«Сколько лет, сколько зим!» - «Вот гостя тебе из Москвы привез. - Шилов брал быка за рога. - Чем привечать будешь?» (Максимов 1). "Haven't seen you out here for ages!" "I've brought you a visitor from Moscow." Shilov took the bull by the horns: "What can you offer us?" (1a).