The only way to bring the planet back from it's ancient slumber.
1) build a factory to send gas into the o-zone layer so light gets trapped on the surface to warm the planet, this will cause the ice caps to melt causing the planet to regain it's water seas and oceans, but they will be only 30 feet deep.
3) bring moss that you find under rocks to mars and place them by or in water beaches.
4) plant life grows and air starts to take over, but still dangerous to breath for a while.
5) thousands of years later complex water life forms in the seas.
6) inhabit mars for farming and science facilitys, not to populate mars or we will kill it just like earth.