How do i download iso/cso files? what apps do i need to download it with? HELLPP!!!?

i have a psp 3001 with 6.35 PRO-A. i saw this video on you tube: http://www.youtube.com/watch?v=mhyKCA978ss.when i downloaded i tried to extract it but there was no extract opion so i downloaded winrar.then i extracted it with winrar and in the video it says that the iso or cso logo should look like a cd with a music note on it.and my logo is just a white page!!!. what apps do i need i already have winrar what else do i need. how do u download it from pspisoz.com what do i doo HELLP!!!!!!!!