There are 2 methods of applying a ppf patch - you can either patch the ISO file or any individual files within the ISO.
With both methods
you need to open the ISO in UMDGen first.
To apply a ppf patch to the whole ISO you use the 'Apply PPF' menu item or toolbar button.
To apply a ppf patch to an individual file, right-click the file and select 'Apply PPF' from the popup menu.
NOTE: To apply ppf's you must open an
uncompressed ISO image.