Hi FNU,
You can use tortoise svn to resolve the conflict. Install version 1.7.15 (this is important). Once that is done installing you can right click the main folder for your project, go to the svn options and click check for modifications. Here you can see what is conflicted and if you want to resolve using your copy or their copy. Then I recommend committing the changes using svn.
Here are the download links for svn
Kind of strange that tortoiseSVN is advised, because you can do the same in the Modeler in the Change-view.