Spawn in at Command Post 4 as a Stormtrooper or Super Battle Droid. Run up the road and take control of CP 3. Rush towards CP 2 and then secure it also. After you have CP 2 under your control you will probally want to search for the nearest tank. Once you have selected a tank, guard the bridge that faces CP 1. Blast the oncoming enemies. When their reinforcement count is low enough charge in and finish off their remaining forces.