'rm' not found in PATH or not executable
Well, at first thanks to the apport of https://unix.stackexchange.com/questions/115743/i-deleted-bin-rm-how-do-i-recover-it
sudo touch /bin/rm sudo chmod +x /bin/rm apt-get download coreutils sudo dpkg --unpack coreutils*
You create a dummy file where the rm should be, an adds execution permission. You download the coreutils application (not sudo needed) and after that you install the files. dpkg will read coreutils package and make the install.