Unless we can figure out how to revive the core to produce a stronger magnetic field there is not much we can do about terraforming the place.
I’ve read speculation of running electrified coils of wire around the north and south poles. Not sure how that would work.
And if the core is iron, maybe a series of deep-drilled h-bombs?
Anyway, we are talking about 22nd century endeavors.
This century we have to solve the propulsion problem. Our rockets are too freaking slow.
And they cost too much.