InfoPath Dev

 I have a SharePoint library with a number of forms that have previously been digitally signed.  I need to make a slight aesthetic change to the form, but when I publish it I am warned that all existing digital signatures will be invalidated.  How do I get the digital signatures to persist in this ...

When I try to open a form in my IP 2007 library, I get the message that   "another user has the form open". The library does not force check out of forms and I have the user's name from attempting to check it out. The user is off-site and although I have elevated privileges, I do not know how to override this lock on this form. ...