Access the HTTP instance for Web Space Server using http://<machine-name>:8080.
Choose Sign In from the Welcome menu.
Click on the OpenID link.
Type the OpenID URL and click Sign In.
Select the Skip This Step Next Time I Sign In to http://machine-name:8080 option, and click Continue.
This accesses to the OpenID site.
Authenticate your OpenID and click Save.
For the OpenIDs provided by Yahoo and many other OpenID providers, you need to register the OpenID by selecting My Account -> Identification -> OpenID.