A Character's Animations are placed in the FitMotionEtc.pac file. You can open a Character.pac, preview the model, open the MotionEtc.pac, and change them as you please.
That Covers the Animation, the PSA work is going to be more complicated. Project Smash Attacks is something you might wanna try to mess around with, but it's really easy once you know how it works.
Look at the resources at the top for the File Partition, and the needed tools.
Okay, thanks for the explanation, seems interesting. Found the entrance in the gallery though.