$ git clone https://github.com/letsencrypt/letsencrypt.git
$ cd letsencrypt
$ ./letsencrypt-auto --help

$ ./letsencrypt-auto certonly --manual --manual-public-ip-logging-ok -d example.org

# manual verification step goes here

$ cp -p /etc/letsencrypt/live/example.org/privkey.pem ssl.key
$ cp -p /etc/letsencrypt/live/example.org/fullchain.pem ssl.crt
$ tar -cavf letsencrypt.tar.xz \
    /etc/letsencrypt /var/lib/letsencrypt /var/log/letsencrypt