Implementing custom SFX into Brawl?

[Cyberlink420]

Hey, all. I've figured out the basics of replacing BGM in Brawl, but what I'd really like to do is add in custom SFX. I know that they're all BRSTM files stored in a BRSAR file, but while I could fairly easily replace the BRSTM files themselves, I've no idea how to convert the BRSAR to a modifiable format such as a RAR, nor how to change it back once the changes have been made. I know that the BRSAR to RAR conversion is possible since I've seen SFX rips, but I've got no clue how to do so. Any help or suggestions would be welcome, especially if it's just a matter of running it through Amdrou's BRSAR program. Of course, if this is all just a fool's errand, then I'd prefer to find that out sooner rather than later so I don't spend too much energy on this.

 

[metaXzero]

Currently, we can't put in moddified SFX back into the game IIRC.