The canonical answer is: You don't. You can only upgrade to it from stable or testing. You do that by editing /etc/apt/sources.list and changing your sources from stable to unstable.
Retirada da página http://wooledge.org/~greg/sidfaq.html#3 .
Boa sorte.
caros, boa tarde.
Sinto ser repetitivo nessa pergunta, mas todas as indicações qeu tenho me levam a esse site:
http://www.debian.org/CD/torrent-cd/
Desejo saber, onde baixo o sid?
Obrigado.