First we need to send a drill team to tunnel toward the planet's core from 512 precise global angles. We fire 200 Billion megatons worth of nuclear bombs to explode precisely at the same time to re-ignite the planet core, and hope to God the EMP and reactivated core tosses up a workable magnetosphere. Having gotten lucky (or blessed) with this success, we wait fifty years to see what comes of that. Meantime, we transport specimens of every successful and beneficial microbe we can to release in specific areas according to terrain and such. Also, we install monitoring stations and comsats in networked orbits (new ones as the EMP and new magnetosphere likely knocked out the present ones and we have cooler toys now anyway). We send in the self-sustaining and self-duplicating nanobot team to explore and network; seperate but cooperative networks for various terrain and subterrain as the search for water procedes and the planet settles into new life from our little jumpstart.

One alternative to the nuclear jumpstart may be a billiard ball maneuver: we drive a new moon into it with enough momentum to reignite the core and figure out how to fit Mars' newest satellite into a network of magnetic and gravitational harmony (and being very careful in this process not to knock Mars or anything else too big from its current path to one likely to collide with Terra Firma before the sun supernovas).

Then send in Chemlawn!