1、刪除redhat原有的yum源
# rpm -aq | grep yum|xargs rpm -e --nodeps
2、下載新的yum安裝包（CentOS的yum源）
注：rmp包版本可能有更新，如出現無法下載的情況，請自行網上找到相對應的高級版本下載使用
# wget http://mirror.centos.org/centos/6.5/os/i386/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
# wget http://mirror.centos.org/centos/6.5/os/i386/Packages/yum-metadata-parser-1.1.2-16.el6.i686.rpm
# wget http://mirror.centos.org/centos/6.5/os/i386/Packages/yum-3.2.29-40.el6.centos.noarch.rpm
# wget http://mirror.centos.org/centos/6.5/os/i386/Packages/yum-plugin-fastestmirror-1.1.30-14.el6.noarch.rpm
3、安裝yum軟件包
# rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
# rpm -ivh yum-metadata-parser-1.1.2-14.1.el6.i686.rpm
# rpm -ivh yum-3.2.27-14.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.26-11.el6.noarch.rpm
注意：最後兩個安裝包要放在一起同時安裝，否則會提示相互依賴，安裝失敗。
4、更改yum源 此處使用網易的CentOS鏡像源
# cd /etc/yum.repos.d/
# wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
# vi CentOS6-Base-163.repo
編輯文件，把文件裏面的$releasever全部替換爲版本號，即6 最後保存！或者直接把下面的內存拷貝到CentOS6-Base-163.repo文件中即可（已經修改好）
:%s/$releasever/6/g
#########################################################################
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-6 - Base - 163.com
baseurl=http://mirrors.163.com/centos/6/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#released updates
[updates]
name=CentOS-6 - Updates - 163.com
baseurl=http://mirrors.163.com/centos/6/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that may be useful
[extras]
name=CentOS-6 - Extras - 163.com
baseurl=http://mirrors.163.com/centos/6/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-6 - Plus - 163.com
baseurl=http://mirrors.163.com/centos/6/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#contrib - packages by Centos Users
[contrib]
name=CentOS-6 - Contrib - 163.com
baseurl=http://mirrors.163.com/centos/6/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=6&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirror.centos.org/centos/RPM-GPG-KEY-CentOS-6
#########################################################################
5、清理yum緩存
# yum clean all
# yum makecache #將服務器上的軟件包信息緩存到本地,以提高搜索安裝軟件的速度
# yum install vim* #測試域名是否可用
到此，Redhat6.3就可以使用CentOS的yum源在線安裝軟件了！