You will need an iso image of the game to see the files inside it. If you want to decode pmf files then you can use the above mentioned codecs. Google for "pmf codecs" or something similar and you'll be in for a treat. You can then use them in anyway you want.
* To take a dump of the UMD in your psp, use UMD Dumper or something similar.
* If the pmf files are not residing in the iso folders e.g. they are inside .BIG and volume files, then you'll need extractors written specifically to search and extract them.
Just ask questions the way you encounter problems and we'll help...promise

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