Training the mind and the will

I teach science at a Catholic school. Our motto is "Faith, Knowledge, Virtue". A common phenomena to all teachers is the student who is very bright. He understands the material quickly and can perform well on tests. However, he constantly neglects homework assignments. As a result, he earns a grade of perhaps a C or even a D when he could easily make an A with simple effort. Many of us say, "He COULD earn an A, but he just doesn't try."

I've come to realize that he really CAN'T get a better grade on his own. Just like another student who really exerts himself but struggles to understand the material really CAN'T get a better grade on his own. BOTH require significant effort on their part and significant guidance on the part of teachers and parents.

The reason is that a person has two spiritual faculties of his soul: the intellect and the will. By his reason, [the human person] is capable of understanding the order of things established by the Creator. By free will, he is capable of directing himself toward his true good. (CCC 1704) A student who really works hard and scraps it out all quarter to earn a C+ is struggling particularly with a fallen intellect. I often recognize this struggle in students and council extra effort and practice for them to achieve a better grasp of a given concept. Another student who immediately understands a topic but fails to do his homework is struggling particularly with a fallen will. But, I have a default attitude of "Just get it done!" with this second student.

I'm realizing more and more that the second student needs to exert additional effort and practice (along with external structure and monitoring) just as much as the first. The will must be trained just as hard as the intellect. There is no switch to flip from "slacker" to "on the ball". Human virtues are firm attitudes, stable dispositions, habitual perfections of intellect and will that govern our actions, order our passions, and guide our conduct according to reason and faith. ... The moral virtues are acquired by human effort. They are the fruit and seed of morally good acts. ... Human virtues acquired by education, by deliberate acts and by a perseverance ever-renewed in repeated efforts are purified and elevated by divine grace. With God's help, they forge character and give facility in the practice of the good. (CCC 1804, 1810, emphasis added)

I'm starting to get the "Faith, Knowledge, VIRTUE" thing a little better. Now, how do I teach it?