Setting up X server on Centos6 minimal

From my webhost's knowledgebase:

If CentOS has already been installed without a graphical interface, 
you can install this with the following commands:

$ yum groupinstall "X Window System" "Desktop" "Desktop Platform"

$ yum install gdm

If you would like this to be the default runlevel, you can edit 
/etc/inittab and set the default level to 5 instead of 3:

$ vi /etc/inittab

Change:
id:3:initdefault:

To:
id:5:initdefault: