1. Go to Grades > Enter Grades by Student and enter the student in question.
3. In the Show: drop-down, select All Columns.
4. Unmark "Use in Calculations" and "Print Grade on Transcripts" next to the class that you do not want to use grades for. 
5. You can also choose whether or not to use this grade on report cards by marking or unmarking the box "Print Grade on Report Cards."