Trying to shave the lip of this bookshelf

I've been trying to shave down the tip of this bookshelf so that it will in the corner of my room, I don't care how it looks or what will be damaged as long as the structure is sustained. I don't have any power tools unfortunately so just looking for a barebones methodhttps://ibb.co/JqKTtKH via /r/DIY https://ift.tt/3bcorq8