Cheat Engine also works, so it's not just Artmoney that you can use. I can't confirm this for other positions, but I know, for a pitcher, and I've tried this on multiple separate runnings of the executable and different characters, that the following addresses work in Cheat Engine:
Pitching Skill Points: 019165A8
Batting Skill Points: 0191659C
Fielding Skill Points: 019165A0
Running Skill Points: 19165A4
If somebody could confirm whether these addresses work on their machine and/or on other positions, that'd be great.