General Grievous: Rookies
As you start on the fiery planet, wait for the giant snake to come out of the left-most hole and zap it with your laser, but only when hearts appear over its head. After doing this a few times, it will break the fan grate to the snake's immediate right.
Use the resulting rubble to create a bridge to the next hole.
From here, again, shoot the worm when the hearts appear. More rubble will be created after you defeat it, allowing you to build a staircase up to the platforms above. Climb up and use the clone with the rapid-fire gun to destroy the gold fence.
Use the grappling hook to swing over to the next platforms, and use the same rapid-fire clone to shoot the gold bricks you see here. Walking through this hole will take you back to the top of the settlement.
To the right of the large door in front of you, there's some rubble - build it to create a panel. By now you should recognize the blue droid. Attack him so his head pops off and you can activate your just-created panel.
Walk all the way to the back of the new room and to the right to enter the next challenge. Destroy all the droids in this room, noting that some are wielding weapons that must be dislodged with your chain attack first.
Time to split up. As the lone clone, run through the highly ominous army of droids. Don't even bother attacking them. Instead, run down the hallway, doing your best to avoid the droids, until you reach a big gold box outside. Shoot it with your lasers until it reveals the invincibility cart.
Streamroll the droids as you head back inside the ship, and then switch over to the rest of your team.
Head to the left of the room to assemble the electrical components on the wall, and then press the switch that appears right next to it. Walk inside the room you just opened, and grab the hook up high, near the gate. Shoot the droid on top of the cart and hop on in his place.
Drive the cart back into the central room, and dock it on one of the three orange pads. Next, climb up the staircase in the back of the room, destroy the objects on the blue-and-white checkered path, and push the power module to the end of the path. Then flip the newly activated switch.
Go to the new door, shoot your bazooka at the gate, and take control of the cart here. Guide it to another orange pad. This will open up the laser field to your right, which is where your other cart should be. Switch to the clone who's already on top, and have him ride it into the final orange pad.
And that's all she wrote!