When you are rushing the hill under the easy difficulty setting, just rush up the right side. If you try to kill everyone first it will not work; they just keep appearing.

Note: The VC appear on both sides after eliminating the first two turret bunkers; rushing up the right side does not work under the normal or hard difficulty settings. Instead, stay prone and crawl up the middle. The turrets cannot see you, and neither can the VC because they are being suppressed by the rest of your platoon. Another easy way to climb is to first shoot as many of the little bunkers and people as you can on the hill from the left side in prone position until you reach the first bamboo patch. Then, run up in standing position and drop the grenade. It is easier to beat the hill with two players. After the hill and while you walk through the rice patties and village, watch out for enemy snipers. They are on you all the time.