You can manually add and edit enrollment rows for students, to update existing enrollments, or to add new/future enrollments.
To add/edit enrollment rows:
1) Navigate to Core. 2) Select Users/Access > Profile > Edit User Profile Data. 3) Search/select the student. 4) Scroll to the lower left under System Information. 5) Click Student Enrollment. 6) Click Edit to the right of any enrollment row to update (ex. Grade Level, Repeated). 7) Click Enroll in School in the upper right to add a new enrollment row. 8) Be sure to Save any changes.