TWEAK WHEN YOU PLAY HUMAN VS HUMAN

My pal and I are playing a season with our team (LA and Portland). We find the original roster somewhat exagerated on some ratings (dunks, 3pts, speed...). With the original roster, my friend and I have FG% > 60%. And LA more than 50% with 3pters. BUT we find the tweaked roster really too hard to play, maybe interesting, but still some problems (open shots won't fall and more...)

We need to edit the roster by ourselves. We want to decrease some ratings. Is there a way to batch edit some ratings? what software ? or what way to realize this ?

plzzz we need your support!
keep up the good work