A lot of people criticize sports, but I have to tell you the required study tables gave my daughter a lot of structure in college. As a freshman she was required to attend study tables 8 hours per week. Every night she’d go to the library area set aside for athletes, check in, set up her area with her computer, tablet and books, and dig in. One big advantage was studying with another student (different sport) who missed class about once a week and she taught him the material, which reinforced it for her. She went to office hours with the prof and TA, she studied for hours. She was in bed at 10 pm. She still had a social life and joined a sorority, but studying came first.
It takes work. Encourage your child to meet with the professor to review the work graded to date, to set up a plan, to get tutoring from a grad student, to watch Khan academy youtubes, to get into a study group.
IMO, if he’s going to drop 2 of his 4 classes, he might as well drop out because he’s not taking college seriously.