Okay,this is how it works.Inside the alloy MDL0,you'll find a folder called texture or texture1.Inside that you'll find some crap.Rename those to what you have in the texture(80).brres.(it might not be 80)Then edit the textures inside the texture.bress.
I recently made a new brstm and i put it in mah brawl.When it plays,it'll switch to another song,then another.Then when i play it in Brawlbox,it plays fine.I usume its a prob with the File patch code,but if not could someone help???/