Complex sentence: After receiving a failing grade in school, he uses his IMSAI 8080 microcomputer to break into the district's computer system, changing his grade and that of his friend and classmate Jennifer Mack (Ally Sheedy).
Split into simpler sentences: After receiving a failing grade in school, he uses his IMSAI 8080 microcomputer to break into the district's computer system. He then changes his grade and does the same for his friend and classmate Jennifer Mack (Ally Sheedy).