Land in Montana. There aren't very many people and there are a lot of crazies that say they have been seeing UFO's already. This also means someone else who wants to invade Earth might be in the area, however. Use the swiss army knife to build a house. Use the house to attract people and persuade them to join you. Once they have joined use the PS2 to train them on how to fight.
Convert the house into an undergroud base using the swiss army knife, (watch the 3rd episode of Macgyver). Jump in spaceship and go to Mexico. Convert Mexicans. Have them cross the border, and convert all instruction manuals to Spanish so a civil war breaks out between the Mexicans and Americans. Wait. Then attack using secret base.
Next time: How to cook food in the Jungle using Magnets