how to commit ...

OK, hate to admit this, but I'm ready to make a change to a portfile and, with the permission of the port maintainer, am ready to check into svn. But I don't know how, and I can't find any docs on macports.org on how to do this. I've used svn before ... What is the server? (svn.macports.org?) What is the path (just /trunk/...)? Log in with my macports id? username or username@macports.org? Is there any way to do this without having to check out a working copy (I'd rather just change a Portfile and the Portindex locally, check it works, and then check in the Portfile back into trunk)? Good doc to have on the wiki. JDO