Most schools have some kind of tutoring program, where the student can get help outside of class time. That means the student will have to sacrifice some of their own free time to spend going over problem topics. Often the tutors are older students who are volunteering their time to sit in a study hall corner, going by a schedule, being there to help whoever needs it. Some effort must come from the student himself before anything really changes.
And I’m sure if one looks hard enough, there are plenty of YouTube videos that can cover any subject you need.
Wish I had that when I went to school.