[pmwiki-users] Private Groups?

[Kai Buehler]

Hello,
I read

"Setting read protection to a group
To create a group that is not visible to the public, set a password for 
the read permission on the GroupAttributes page. Enter the following into 
the browser's address bar for a group PrivateGroup to access its group 
attributes (passwords):
PrivateGroup.GroupAttributes?action=attr "

on http://www.pmwiki.org/wiki/Cookbook/PrivateGroups, but I do not 
understand WHERE to do this.

Could someone explain this to me?

Thanks!
Kai.