pico /var/named/your.dns.zone.com.db (add A record for host)
pico /usr/local/apache/conf/httpd.conf (may not exist anymore)
also might help license
You can also run: pico /etc/sysconfig/network and change it there.
Then run: hostname yourhost.name
Then reboot the server.
If you have a VPS than you might need to contact the VPS provider to change it from the VPS control center.