Is it possible to replace the cinematic_1 and endcredits mp3 files with music of my own so I can hear the custom music in single player JA?

One other thing, how would I replace models in JA SP like Rosh, Tavion, stormtroopers, Alora, reborn and cultists so I could have Rosh as a Anakin model and Tavion as a Darth Malak model and so on?

Any help would be appreciated. Thanks

Yeah just unpack the assets.pk3 files and then in the sound folder replace the songs with yours, then repack.