https://github.com/downloads/miyamuko/git-merge-changelog-for-windows/git-merge-changelog.exe

1. Add following entry to your ~/.gitconfig.

   [merge "merge-changelog"] name = GNU-style ChangeLog merge driver driver = /path/to/git-merge-changelog.exe %O %A %B

2. Set merge strategies for each changelog files.

   ChangeLog      merge=merge-changelog
   ChangeLog.txt  merge=merge-changelog
   

1. Install MinGW/msys

2. Try:

   git clone https://github.com/miyamuko/git-merge-changelog-for-windows.git
   cd git-merge-changelog-for-windows
   sh build-git-merge-changelog-exe.sh