dont want to delete old files

I want to keep my old files in the installation directory as it is and only replace few files.Here when i am trying to update it removes all older files and then puts new files.So can i update few files only and keep other files as it it?

Yes, if you follow the step-by-step walkthrough article you'll see it says to add all files for every version to wyBuild. wyBuild is smart enough to know which files to add, which files to delete, which files to patch, and which files to leave untouched.

Does that make sense?