EDIT: I'm rewriting this answer based on some of the information you updated in your questions.
First, to forcibly unlock files it's not enough to simply --force the commit. You use --force with the unlock command and you have to use it on the exact URL that you want to unlock. Unfortunately, this is the only way to do it unless you have access to the repository. If you can access the repository directly, you can use the svnadmin command as displayed here:
svnadmin lslocks /path/to/repository
This will display the locked files. To unlock:
svnadmin rmlocks /path/to/repository /project/path/to/locked/file
If you don't have direct access to the repository, you remove the locks one at a time like so:
svn --force unlock svn://url.to.repository/project/path/to/locked/file
Once you're ready to check in, you can list the files directly that you want checked in instead of just doing the default directory. This will allow you to check in only the modified XML files while ignoring directory structure changes, additions, or whatever else it is that you don't want checked in (added unlock example too):
svn --force unlock svn;//url.to.repository/project/janes_subdir/jane.xml
svn ci -m "Whatever Log" foo.xml junk.xml my_subdir/*.xml janes_subdir/jane.xml