Humanity eventually colonizes the whole solar system and experiences a time of unprecedented prosperity. An alien robotic fleet begins destroying every colony, cleaning every trace of biological/organic compounds from every planet and moon (for as-yet unknown reasons). As humanity is on the brink of collapse and the resistance in the Jovian System begins to crumble, humanity dismantles the moon and Mercury (the Aliens don't possess any type of superluminal travel) to build a complex "bubble" around Earth and a massive warp drive (Alcubierre-like warp engine) to escape the solar system.
Since there is nothing left for humanity in the solar system, they decide to make the Sun explode to protect the galaxy from this fleet.
How can humanity make the Sun explode (destroying everything inside the heliosphere) ?