Assassination Classroom Foot Festival

Let's take this Foot Festival to the extreme with the idea of killed Kono-sensei in Assassination Classroom. If you would with Nagisa and the rest of Class 3-E of Kunugigaoka Junior High, how would plan to sneak in to take down Koro-sensei without him noticing your presense? I do want to use my stealth skills to find such female bare feet and their footwear without being detected like the female English teacher, Irina Jelavić, such sexy feet from an young woman.