You'll need to wait a little bit in order for the gates to open, so you can start the battle. Your first order of business is to capture the two bases at the foot of Mt. Dingjun, which is easily done by defeating the officers inside of them. Note that near the beginning of the battle, there will be ballistae placed near the foot of Mt. Dingjun, so if you happen to approach it, be careful of them.
Zhuge Liang will chime in and say the enemy is only facing forward and it's a good idea to capture Mt. Tiandang, which is in the northwest corner of the map. Follow the west side of the map, taking out any officers along the way, which includes Xu Huang and Wang Yi. At the top, fight and defeat Zhang He to capture Mt. Tiandang.
Climb the stairs and you should see a marked circle on the ground. Stand inside of it and press the button to make your character automatically head down the hill and land inside Mt. Dingjun. Once you're inside, there will be a few officers in the way, including Xiahou Yuan, Xiahou Ba and Guo Huai. Defeating them will let you capture the place.
With Mt. Dingjun finally in your hands, all that is left is to go and defeat Cao Cao. Note that upon exiting Dingjun, you might want to go around and destroy the ballistae that were placed at the beginning of the battle. There should be a garrison to the south of Cao Cao's, so go there to find a few officers, then head to Cao Cao to finish the battle.
|You need to defeat Cao Xiu and win the battle in order to get this star. Cao Xiu is not on the battlefield in the beginning, but will appear as reinforcements later on. He appears on the eastern side of the map, so when he does show up, head over there and take him out quickly.|