phase 1: thicken atmosphere and warm planet
• tons of SF6 or something even more potent, or some process for the Mars surface that would exponentially increase its effect
• dense gas stays in thin atmosphere and insulates planet, warming it, causing CH4 and H2O to melt and make the atmosphere bigger
• larger atmosphere better insulates planet, making the nights warmer.
• clouds eventually form and cool planet so days are not too hot.

phase 2: hardy primitive bacteria
• change chemistry at the surface

phase 3: photosynthetic lichens and bacteria
• begin to change atmosphere from reductive to oxidative

phase 4: hardy plants and insects
• begin to form ecosystem and continue to change atmosphere

phase 5: add trees and animals; refine climate