I want to modify this file, following PathFinder's instructions
however, it's not XML whatsoever. Looks more like some binary format.
What am I missing?
Here are the instructions from the PathFinder manual
If you’re feeling more geeky, edit the preference file com.apple.loginwindow.plist and add the following lines:
<key>Finder</key> <string>/[path to]/Path Finder.app</string>