An easy way to get far in Order 66 is to kill the troops with rocket launchers and the Imperial Sentinals (guards with the staff). Just use Repulse when a rocket is sent at you and it will go back and hit the troop. The sentinals are harder because they can withstand a LOT more damage than everybody else. Try to force choke them or Push them. If you have Pummel maxed out, that helps too. You shouldn't have too much trouble with the other troops except for Jump Troopers. They can take a beating. Take them down next. The regular troops are easy.