Uh...You could erase/format your card, I guess. If your intention is to have vBrawl with custom music, then you need to just make a new .gct that just has the file replacement code and nothing else. Then you just put your .brstms in a private>wi>app>rsbe>pf>sound>strm folder.
RSBE01.gct goes into the "codes" folder.
You'll also need to put a copy of Gecko OS in the "apps" folder. PM comes with one.
http://midenhall.com/2009/07/09/starter-guide-replace-brawl-music-using-an-sd-card/
Basically, make a text document with the file patch code and put it through the GCT maker.
https://www.dropbox.com/sh/yzhr8jcvc3g3lep/Ke45fuantz
You have to start the text document with the lines:
RSBE01
Super Smash Bros. Brawl (NTSC)