Spawn at one of the northern commands posts 1 or 2, as either as a Super Battle Droid or Droideka. Capture command post 3 as this one isn't as secure as the other ones. It's best to secure the command posts from 1-3 as Count Dooku will help you during the battle. It is highly advised to play as a Super Battle Droid through the level. Don't be discouraged if you only have two of them. Hunt down and destroy the remaining Wookies.