Using the amazing Polish Space Agency, I nuke near the asteroid. Before this, we will observe the asteroid and use this knowledge to best understand the effect of a nuke on it. I send like 10 rockets up with nukes, because 9 will fail, but 1 will succeed. This will happen when the asteroid is close enough that we will succeed. 1/10 rockets blow up, so using 10 means we shouldn't lose. It will blow up near the asteroid and deflect it away from earth. This will stop the threat and leave us be. Ez win for me.
Description is more important that visual aid. We are waiting until it's closer, to make sure it is going to hit, before we deflect it.