Psp save file modding help.

I this one guy I know downloaded a Monster Hunter save file off of some website, and the file was clearly hacked. I searched the net, and i found a program that will mod it from your psp but you have to have 1.5 firmware, and you cannot downgrade unless you have like 2.6 or below. I got 3.95, and anyway, I want to be able to do this from my computer. any knowledge, or programs to pass on?

anyone?

I've never modified a safe game of mine. But I believe you can just download savegames from www.gamefaqs.com and put them on your memory stick.