Hacking wordpress on my server

Okay, basically, I run a site. One of the features of this site is that we allow some of our members to have wordpress blogs as sub domains of our site. We’ve never been very big so wordpress mu hasn’t been appropiate, we’ve just used fantastico to install it and then given them there own sub domain and let them do whatever they want with it.

Alot of these blogs have proved very successful during there times and even after dieing they’ve been left as an archive due to the amount of and level of, content on the site.

However, I now want to rejig things a bit and archive some of the older blogs which have been inactive for months or even years. Of course I could move things around using phpmyadmin, but it would be so much easier if I could just download the xml file of posts and re-install it in a new wp installation.

I can do this with the peoples blogs who are still around as obviously I can just ask them to download the xml file and give it to me, but I can’t do this with the blogs which are inactive and the authors haven’t been seen for ages.

So basically, seeing as I have full ftp and sql access, I figure there must be a way for me to get into the wp admin and download the xml file, but I can’t figure out how.

Any tips?

Hopefully this hasn’t come across as me being a hacker trying to get access to peoples wordpress installations, or controvined any of your forum rules, just trying to make my life easier really.