http://7r2frwg2nrpdknemkjxkzqmoudsjqqemwkzzkhymuqcln7noyuybyeqd.onion/takeover-sh/index.html
I recommend SystemRescueCD, which comes with many useful tools (you have to loop mount the ISO and then use unsquashfs). Obviously, whatever you pick has to fit into free RAM, with room to spare. If your chosen rescue environment has,/lib/modules you may want to get rid of it to save space, as its kernel modules won’t be useful on the host kernel anyway.