Instructions
Instruct the worm closest to the left side of the battlefield to walk to the left. This is the first worm you control, and it only has 1 HP. Walk right off the ledge into the cheese crater where the crate and the sentry gun are sitting -- you need to land on the crate to collect the Pneumatic Drill. The fall causes the worm to die, but the team gets the item.
Walk the second worm you control, the last one with only 1 HP, to the edge of the ledge to the right. Jump from the ledge so you land on or next to the sentry gun. The fall kills the worm and the resulting explosion sends the sentry gun into the water.
Have your third and final worm, the one with 30 HP, walk to the ledge on the right. Walk off the edge so you land on the crate and collect the Ninja Rope. Use the Ninja Rope to hook onto the satellite hovering in the top right corner -- aim for the fin closest to you.
Pull up on the rope so you are hanging in midair. Lower yourself toward the water and swing to the left so you are under the wheel of cheese. Quickly release the Ninja Rope and engage it again to catch yourself on the underside of the cheese. The button for this is "A" for Xbox 360 and "X" for PlayStation 3.
Keep yourself very close to the cheese by riding up on the rope, then swing back and forth. When you are on left side of the swing, release the rope and engage it again by double-tapping the "X" or "A" button. Repeat until you are just at the cavern in the middle of the cheese's underside.
Give the rope some slack so you are hanging low enough to swing yourself up into the cavern. When you are in it, release the rope and shoot it out again so you are hooked to one of the inner walls in the cavern. Send yourself up into the cavern and onto the crate using the Ninja Rope. The crate contains the Armageddon item.
Use the Pneumatic Drill from the crate's location to drill down into the cheese. This will protect you later on. When you are finished drilling toward the bottom of the cheese, use the Armageddon item. This will kill the six enemy worms on top of the cheese.