title: Overwrite file from svn:externals
body: <p>I'm using svn:externals to include code from another project - for which I do not want to commit changes to.</p>
  
  <p>One of the files included by svn:externals needs a small change (just a line) to work with my current project. So I want to commit this to my own SVN.</p>
  
  <p>How do I do this? If I try and commit as things are now, it tries to commit my changes to this file to the owners SVN - which obviously isn't possible.</p>
  
  <p>Should be easy I guess? I'm using TortoiseSVN on Windows</p>