from the CLI
http ON
service controlcenter restart
Access the GUI over HTTP://
Remember to issue http off once you get the certificate assigned.
From the 8.03 manual:
http
The http command enables or disablesHTTPaccess for your appliance. By default,
each appliance has the HTTPS Web server enabled and the HTTP Web server
disabled. Using the http command has no effect on HTTPS access. After executing
the command, the Control Center must be restarted with the service command
for the change to take effect.
The http command has the following syntax:
http <on|off>
where on enables HTTP access and off disables HTTP access.
Type help http from the appliance for online assistance.