替换  /etc/apt/sources.list

deb http://old-releases.ubuntu.com/ubuntu precise main restricted universe multiverse    
deb http://old-releases.ubuntu.com/ubuntu precise-security main restricted universe multiverse    
deb http://old-releases.ubuntu.com/ubuntu precise-updates main restricted universe multiverse    
deb http://old-releases.ubuntu.com/ubuntu precise-proposed main restricted universe multiverse    
deb http://old-releases.ubuntu.com/ubuntu precise-backports main restricted universe multiverse    
deb-src http://old-releases.ubuntu.com/ubuntu precise main restricted universe multiverse    
deb-src http://old-releases.ubuntu.com/ubuntu precise-security main restricted universe multiverse    
deb-src http://old-releases.ubuntu.com/ubuntu precise-updates main restricted universe multiverse    
deb-src http://old-releases.ubuntu.com/ubuntu precise-proposed main restricted universe multiverse    
deb-src http://old-releases.ubuntu.com/ubuntu precise-backports main restricted universe multiverse

以上直接覆盖原source.list内容

不会操作的参考这个