Change Zoneminder Port

This is what I did to use another port in zoneminder (under apache):

1- edit /etc/apache2/ports.conf, then change both "NameVirtualHost :80" and "Listen 80" to the new port
2- edit /etc/apache2/sites-enabled/000-default and change "<VirtualHost :80>" to reflect the new port
3- restart apache "service apache2 restart" (or sudo systemctl restart apache2)

Hope it helps,