Back when we were all using ndspatcher and loadme or the first neoflash carts came around to get more than 2 or 3 roms to fit or to even get them to fit in the first place people generally pulled apart the rom and replaced things like the soundfile, that was just in reference to that.
If a 0k file will not cut it then you can try deleting the end of the file or using one fo the very small ones from rockman ZX.