Nice and simple, just play conquest and go for the objectives.
Things to note:
-Staying in a tank will help greatly.
-Spawning on squad when they are capturing the flags will also give you points.
-Play assault kit, its has great anti-tank capability ( good for flag areas )
-Playing in a good squad will grand you high squad bonuses at the end of the match.
It should take around 3-5 Hours based on your performance in-game.
Good luck!