[DannyTN]

Crash it into Mars. Do this enough time and Mars gains water and increases mass to retain more atmosphere.

[Jack Hydrazine]

Since the Martian atmosphere is primarily CO2 why aren’t they being subjected to AGW like Venus and the Earth?

[Lucius Cornelius Sulla]

‘Crash it into Mars. Do this enough time and Mars gains water and increases mass to retain more atmosphere.’

Fuel for changing the asteroid's orbit obtainable from Jupiter's atmosphere. Ice in the asteroid belt is the key to terraforming Mars.