You can do it if you SSH in and alter the ssh_config file in /etc, (SU to root, and then type joe /etc/ssh_config and scroll down till you find the port number)
I'm not sure if that will be over written everytime there is a new up2date though.
thats not all, you must also set a filter roule because the allowd networks in System/Settings/ssh in the webinterface dont work anymore and there is a second sshd_conf file in /usr/local/etc but i dont no why. I think for recovery.
