iptables -I INPUT -p tcp --dport 10000 -j ACCEPT && /etc/init.d/iptables save
cd /home
rpm -ivh http://softlayer.dl.sourceforge.net/sourceforge/webadmin/webmin-1.470-1.noarch.rpm
Ubuntu/Debian

Steps:

cd /home && wget http://prdownloads.sourceforge.net/webadmin/webmin_1.470_all.deb
apt-get install libnet-ssleay-perl openssl libauthen-pam-perl libio-pty-perl libmd5-perl
dpkg -i webmin_1.470_all.deb
iptables -I INPUT -p tcp --dport 10000 -j ACCEPT && /etc/init.d/iptables save
iptables-save
On Ubuntu you will need to change the last two lines to:

iptables -I INPUT -p tcp --dport 10000 -j ACCEPT
iptables-save