If you're trying to follow the tutorial, after you installed mod_security then run these commands in SSH:

Code: 
wget -O /usr/local/apache/conf/modsec_rules.tgz \
 http://www.uhgbug.com/files/modsec_rules.tgz;
tar xvfz /usr/local/apache/conf/modsec_rules.tgz --directory \
/usr/local/apache/conf/
/usr/local/apache/bin/httpd -k graceful