1）首先，需要移除系统注册相关软件
∘ 查看相关软件：rpm -qa | grep subscription-manager
∘ 移除相关软件：yum remove subscription-manager
2）为了使用CentOS提供的yum源，需要删除系统自带的yum
∘ rpm -aq | grep yum | xargs rpm -e --nodeps
3）从Centos上下载安装yum
∘ wget http://vault.centos.org/6.0/os/x86_64/Packages/Python-iniparse-0.3.1-2.1.el6.noarch.rpm
∘ wget http://vault.centos.org/6.0/os/x86_64/Packages/yum-metadata-parser-1.1.2-14.1.el6.x86_64.rpm
∘ wget http://vault.centos.org/6.0/os/x86_64/Packages/yum-3.2.27-14.el6.centos.noarch.rpm
∘ wget http://vault.centos.org/6.0/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.26-11.el6.noarch.rpm
∘ rpm -ivh python-iniparse-0.3.1-2.1.el6.noarch.rpm
∘ rpm -ivh yum-metadata-parser-1.1.2-14.1.el6.x86_64.rpm
∘ rpm -ivh yum-3.2.27-14.el6.centos.noarch.rpm yum-plugin-fastestmirror-1.1.26-11.el6.noarch.rpm
∘ 注意： yum-3.2.27-14.el6.centos.noarch.rpm和yum-plugin-fastestmirror-1.1.26-11.el6.noarch.rpm相互依赖，需要同时安装
4） 使用Centos的yum源更新
∘ cd /etc/yum.repos.d/
∘ wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
∘ 编辑CentOS6-Base-163.repo，将$releasever字段全部替换为6
∘ yum makecache
∘ yum vim* ===> 仅用作测试，观察yum是否可用
5）示例：安装VirtualBox-4.3
∘ 从virtualbox官网下载VirtualBox-4.3-4.3.30_101610_el6-1.x86_64.rpm和Oracle_VM_VirtualBox_Extension_Pack-4.3.30-101610.vbox-extpack
∘ rpm -ivh VirtualBox-4.3-4.3.30_101610_el6-1.x86_64.rpm，发现依赖libSDL
∘ yum install SDL
∘ rpm -ivh VirtualBox-4.3-4.3.30_101610_el6-1.x86_64.rpm，安装成功
∘ 双击运行Oracle_VM_VirtualBox_Extension_Pack-4.3.30-101610.vbox-extpack，安装扩展包
∘ 打开VirtualBox，开始自己的工作