The biggest surprise (for me) from the dart mission was that the asteroid wasn't one big rock. It's more like, dust and gravel and boulders all stuck together with gravity.

As much as I love a certain Michael Bay movie about a rag-tag group of drillers tasked with drilling an asteroid in space, it seems unlikely that would be necessary.

Seems like, the two obvious approaches are a push or an explosion.

Using an explosion to diffuse the parts of an asteroid, and that might be a whole lot easier than previously thought, since the thing is only weakly held together. The other approach of giving it a push seem a whole lot tougher, since they're not rigid.