Did not work. Did exactly what your directions say. Un-zip file and only copy contents of /concrete directory over the existing one in my webroot. Blew up my site. This is because in the tools directory under /concrete there is no /required directory as the instructions indicate. There is however a upgrade.php file but trying that doesn't work either. What should be a very easy streamlined upgrade turns out to be a complete disaster. Now I have to totally re-create my site! Not happy with your upgrade instructions.