Move my fleet into the solar system along the celestial equator, keeping the Sun between my ships and Earth. Once I'm on the opposite side of the Sun, at the same distance and speed as Earth, three of my ships (tumbling and on a communications blackout) drop out of formation and let the Earth catch up with them.

Once they're in range, the ships power up, right themselves, and start destroying satellites with nuclear weapons. Anything with heavy traffic, that appears to be a communications platform, is a priority target (though analyze the frequencies used). Anything sending a constant carrier wave, rather than occasional bursts of data, is a secondary target. Anything else is a target of opportunity.

The nukes aren't just destroying global communications systems, they're sending EMP blasts down to the planet below. But the EMPs, while affecting a large area, aren't specifically targeting any region on the ground. Just what's below the satellites they're destroying.

Once they get most of the satellites, they drop into the atmosphere and head towards the oceans, continuing to analyze the frequencies that are being used. Destroy any flying targets of opportunity with conventional weapons (and especially target anything flying towards the ships).

The main fleet will converge on Earth from both sides. The three ships (now resting on the water) should have a good idea of the kinds of enemies we're dealing with and solid analysis of the frequencies and protocols used to communicate. I'm replaying those signals, trying to resolve an image and a sequence of sound that seems to match it.

The main fleet arranges itself around the planet at about the distance of the Moon, outside the Van Allen belts. The vanguard drops under the waves as the fleet sends nuclear weapons to detonate lower in the atmosphere, mainly as EMP weapons this time specifically targeting large cities.

Now the ships drop towards the planet (and the vanguard rejoins the fleet). Pick one of those cities at random and hit it with the superweapon, destroying it. The other ships land and unleash the robot footsoldiers. They operate on Iron Giant protocols, anyone who has a recognizable weapon, or anyone who is acting aggressive, is killed. Anyone else is ignored.

Continue processing the planet until there's no resistance left. Continue analyzing the data, trying to decipher at least one human language. Once communication is possible, present my terms for surrender.