Destroy the earth before the sun can.

Let it swallow the earth then sue it for damages

Preemptive strike! Nuke the sun!

I’ll swallow it myself.

I’ve been broadcasting for help on frequency 1420.3556 MHz since the summer of 1977. No response yet, but fingers crossed.

Piss on it. That will surely extinguish it

Coat the Earth in that bitter stuff they put on Nintendo Switch cartridges so the sun spits it out before it has a chance to swallow.

Earthlings must swallow the sun before it can swallow us

SPF5000000000 sunscreen

Vote against the ballot measure to stop an asteroid impacting Earth, but only in cases where the asteroid is going to adjust Earth’s orbit to be farther away from the sun. As long as I didn’t mess up becoming immortal 5 billion years should be enough time for these opportunities to come up, so I shouldn’t have to bother with other sun-protection measures.

I’ll answer with another question.

War, what is it good for?

I’ve been working on my leg strength so I can hold its jaws open with my feet.

Pull out

Cry and masturbate. Oh wait, you said prevent?

I read A World Out Of Time. That’s one way to solve that problem.