You have to convert the brick to JSON with some programs, and edit them, then convert back, then edit/repackage with RPKG; but it gets too complicated even for me, straightforward data you see in the brick editor is translated into completely different weird numbers (probably hex or something, I don’t even know). It’s just a pain in the ass.
I tried to do it just to add Stuyvesants voice set to the general pool of voiceset since it’s in the same Chunk as all general voices, but I failed, no idea how to do it