Uncomment the baudrate line in JEVOIS:/config/params.cfg, that'll change the baudrate for every module (alternatively you can change it for just one module by making a params.cfg file in the module directory.)
Depending on what you're doing I'd not go all the way down to 9600, though. There's also 14400, 19200, 38400 or 57600. Go with the highest your arduino code can reliably handle.