You can download old releases of pfSense, all the way back to 1.0.1, from here:
Contains newest and old releases.
Restarting OpenVPN on the CLI of a pfSense can be done using the following command:
echo "<?php include('openvpn.inc'); openvpn_resync_all();?>" | php -q
This issues a restart command as if you would via the web-interface.