Yuu must select a "data" folder (Source folder button) which contains sub-directories and files which you want to include in your Patch file. This "data" folder must absolutely respect the original "data" tree aspect, in another way your file will not work.

Then select a destination folder and enter a name for your file (Output file button). PakUnpak adds .patch extension automatically.

Compress: click then on this button and a confirmation message will tell you that your patch file was created.

Choose a source file, Pak or Patch (Source file button)

Choose a destination folder. In this folder, a "data" folder will be created and will contain all the files contained in chosen Pak / Patch file.

Uncompress : click then on this button and a confirmation message will tell you that files are uncompressed.