I remember the good days of hacking SSBB. If your not using hexedit atm, i recommend using it. The xml template support is very useful when trying figuring out the formats of files.
Besides figuring out how to decompress the files, how much do you actually know about them?(headers, relocation tables, string table, etc)
Besides figuring out how to decompress the files, how much do you actually know about them?(headers, relocation tables, string table, etc)