Upgrade Windows 2008 R2 to 2012

We have a remote server that we would like to upgrade from Windows 2008 R2 to Windows 2012 without making the trip and I was wondering if this is even possible. I found an article from Microsoft community (http://support.microsoft.com/kb/962216/en-gb) that states that you cannot but they mention some other items that didn't relate to the question. Has anyone performed an upgrade from an ISO image? If not, it will be on our task list of things to do during our next trip....sigh.