change hostname on a linux machine -centos

I want to change my Linux hostname from Linux01 to Linux03

[root@Linux01 Desktop]# vi /etc/sysconfig/network

[root@Linux01 Desktop]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=Linux03

RESTART THE SERVER NOW. AFTER REBOOT

[oracle@Linux03 Desktop]$ hostname
Linux03

[oracle@Linux03 Desktop]$