In addition to learning basic ASL, meet with your student to develop short hand signs for your basic drills such as kumite or self defense drills which would not be common vocabulary in an ASL dictionary or things you would learn in an ASL class. Kumite #1 for example, might be "K" with a twist motion, followed by the number "1".
Without any sign language, observe the following: (1) when speaking to a group of students, always face the deaf student full face regardless of who's question you are anwering. This feels awkward until you get used to it. Point to the person you are addressing while facing the deaf student. It helps with lip reading. English is only about 60% lip readable.
(2) Don't talk with your back to a window or door that lets the sunlight in. When you do that, you are standing in your own shadow and you can't be lip read.
(3) Keep your head still when you talk and don't exaggerate vocal motions.
(4)If your student wears hearing aids, keep background noise low and position your student in the quieter parts of the room. Hearing aids magnify all sound without selecting voice. Your ears selectively pay attention to voice which is something hearing aids can't do.
(5) Always negotiate with the student on how to maneuver around a communication problem.
(6) If possible, suppliment class time with private time. I don't know the rank of your student. You say he has some study. Would it be appropriate for a Jr. Black Belt to volunteer some time once a week? This would expand awareness for the JBB and help fill in gaps. It also helps build relationships in the school.
Good luck. I applaud you and your effort.
The older I get, the better I was!