mine wont work; freezes at css lol

This is a question I have asked that has gone unanswered for too long!!

In a post by ASF1nk; step ONE says:

Open your "common5.pac" file in BrawlBox then click the + sign next to "sc_selcharacter_en"

but i really have no idea how to find or get this common5.pac file..like what is the file called please help anyone? Like i need an easier walkthrough because the only thing thats in my common5.pac folder is sc_selcharacter/char_bust_tex_Iz77/MiscData[46].brres

any help guys?