How do you unlock jedi in star wars battlefront 2

Depends on what the settings are for the battle your playing. by default the settings unlock the "hero" character for whichever player gets 10 points first, and is unlocked for that specific battle from then on (restarting the battle/replaying the battle means you have to unlock it again, only land battles have heroes) if you die as the hero you must wait approximately 2 minutes to play as the hero again.