here is a tut some1 already made http://www.xpgamesaves.com/topic/53792-tut-how-to-mod-money-in-assassins-creed-3/#.UJKzXW9riBw hit the thank button if this helped
XPGHAX is modding ppl gamesave for assassins creed 3: http://www.xpgamesaves.com/topic/53206-assassins-creed-3-gamesave-modding-service/page__p__242544#entry242544