Terraforming a planet takes hundreds of years; we don't have the technology to do that.
And, who will pay for it?
Forget about terraforming, and look into bioforming humans into becoming Martians. That's closer to being doable.
That's OK, the court challenges will take that long anyway.
We dont have the WILL to do it...if we find the will we will find the ways and the means, technological and economic.