Take financial products courses (so you know what stocks, bonds, derivatives etc are in detail), investment analysis & portfolip management (self explanatory), few macro econs (so you know terminology and some basic econs) & basic accounting (so you can read financial reports when released).
Commerce/Something Investment related should be fine. Have a chat with your faculties.
More importantly though, you need good sales skills & do your RG 146.
I would get in touch with somebody/firms in the industry. Feel free to go on linkedin, message top directors and ask them for career advice. If they're nice, ask them if you can shout them a coffee to find out more (don't ask for a job, this is only career advice, if they have something and like you they'd offer).
Scotty
p.s. please don't think of stock brokers as Jordan Belforts children. Most aren't like that and movies tend to hype things.