Count Dooku - Chapter 1 - Battle of Geonosis
All you need to do to complete this stage is destroy the enemies five bases. Some of them start with their shields down. The others you can easily lower. Take a speeder bike and race to the bases with the shields. Stop before them, jump off the bike and walk through the shield. Flip the glowing red switches to disable the shields.
With the shields down you can either grab a larger vehicle to blast away the buildings, hack at the central towers with your lightsaber (which will take a long time), or use the speeder bikes to race between your base picking up proton torpedos and returning to use them on the bases.
Once all five bases are destroyed and the mission is complete you will receive this achievement.