The sources.list would look kinda like this:
deb http://old-releases.ubuntu.com/ubuntu/ feisty main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ feisty main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ feisty-updates main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ feisty-updates main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ feisty-backports main restricted universe multiverse
deb http://old-releases.ubuntu.com/ubuntu/ feisty-security main restricted universe multiverse
deb-src http://old-releases.ubuntu.com/ubuntu/ feisty-security main restricted universe multiverse
